JPH0291836A - Device and method for recording and reproducing - Google Patents

Abstract

PURPOSE:To remove the noise component caused by vibration by impressing a voltage on a recording medium having an electric memory effect from a probe electrode which is driven in a circular motion and performing recording and reproducing. CONSTITUTION:Electric power from a pulse power source 108 is supplied to the probe electrode 102 whose distance with the recording layer 101 of a recording medium 1 is kept constant by a piezo-electric element and whose movement in X, Y and Z directions is controlled by an XY scanning driving circuit 109 and a fine adjustment control mechanism 107 to perform a spiral motion and a counter substrate electrode 103 on the layer 101 opposed to the electrode 102. Thus, the voltage is impressed on the layer 101 having the electric memory effect made of monomolecular film and monomolecular layer built-up film being an organic compound from the electrode 102, and recording and reproducing are performed. Since the probe electrode is so constituted that it does not perform reciprocating motion but the circular motion, the vibration of the probe electrode can be prevented from occurring and the noise component caused by the vibration can be removed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording/reproducing apparatus and a recording/reproducing method.

More specifically, the present invention relates to a recording/reproducing apparatus and a recording/reproducing method using a recording medium that has a layered structure of an organic compound between a pair of electrodes, one of which is a probe electrode, and has a memory effect on voltage and current switching characteristics.

[Conventional technology]

In recent years, the use of memory materials has become a core part of the electronics industry, such as computers and related equipment, video disks, digital audio disks, etc.
The development of these materials is also progressing very actively. The performance required of memory materials varies depending on the application, but for boat fishing, there are the following: - High density and large storage capacity - Fast response speed for recording and playback - Low power consumption - High productivity and price is cheap, etc.

Until now, semiconductor memories and magnetic memories were mainly made of magnetic materials and semiconductors, but with the recent advances in laser technology, inexpensive and high-density optical memories using organic thin films such as organic dyes and photopolymers have been developed. Recording media have appeared.

In addition, a proposal for a molecular electronic device in which a single organic molecule has functions such as a logic element or a memory element was announced, and Langmuir's technology, which is considered to be one of the construction techniques for molecular electronic devices, was announced.
Research on Projet membranes (hereinafter abbreviated as LB membranes) is also becoming more active.

The LB film is made by laminating organic molecules one molecular layer at a time, and the film thickness can be controlled in units of molecular length, making it possible to form a -like, homogeneous ultra-thin film. Many attempts have been made to use the LB film as an insulating film to create devices that fully take advantage of this feature.

For example, tunnel junction devices with metal-insulator-metal (MIM) structures [G, L, Larkins et al., T
h1n Solid Films, 99. (198
3)] and metal-insulator-semiconductor (MIS) structures with light-emitting devices [G, Roberts, Ele.
ctronics Letters, 20.489
(1984)] or switching elements [N, J, T
homsa etal,, Electronics
Letters, 20.838 (1984)]. Although device characteristics have been investigated through a series of these studies, the lack of reproducibility and stability, such as variations in characteristics between devices and changes over time, remain unsolved problems.

Conventionally, the above studies have focused on fatty acid LB membranes, which are relatively easy to handle. Recently, however, organic materials have been created one after another that overcome heat resistance and mechanical strength, which were considered to be inferior until now.

As we progressed with our research, we became able to fabricate a thin and uniform dye insulating film.
They have even discovered elements.

On the other hand, recently, a scanning tunneling microscope (hereinafter abbreviated as STM) that can directly observe the electronic structure of surface atoms of a conductor has been developed.
ticaPhysica Acta, 55,726
(1982)] single crystal.

It is now possible to measure real space images with high resolution regardless of the amorphous material, and it also has the advantage of being able to observe with low power without damaging the medium due to current.Furthermore, it can operate even in the atmosphere, and can be used for various materials. Since it can be used for a wide range of purposes, it is expected to have a wide range of applications.

STM utilizes the fact that a tunnel current flows when a voltage is applied between a metal probe (probe electrode) and a conductive substance and the probe is brought close to a distance of about 1 nm.

This current is very sensitive to changes in the distance between the two. By scanning the probe while keeping the tunneling current constant, it is possible to draw the surface structure in real space (at the same time, it is possible to draw various information about the total electron cloud of surface atoms). In this case, the resolution in the in-plane direction is 1 degree.Therefore, by applying the STM principle, it is sufficient to perform high-density recording and reproduction on the atomic order (several people). In this case, the recording and reproducing method is particle beam (electron beam, ion beam).
Alternatively, a method of recording by changing the surface state of an appropriate recording layer using high-energy electromagnetic waves such as X-rays and energy rays such as visible and ultraviolet light, and reproducing it with STM, and a method of changing the voltage-current switching characteristics of the recording layer. A method has been proposed in which recording and reproduction are performed using STM using a thin film layer of a material having a memory effect, such as a π-electron based organic compound or a chalcogenide. (Unexamined Japanese Patent Publication No. 63-161552
, Japanese Unexamined Patent Publication No. 63-161553) [Problem to be solved by the invention] However, in the conventional method applying STM, recording and reproduction were performed by linearly reciprocating the probe electrode in the X direction or the Y direction. There was a problem in that noise in recording/reproduction signals increased due to vibrations generated at the location where the probe electrode was reversed. Also,
There is also a problem in that near the point where the probe electrode reverses, the speed of the probe electrode decreases, so the recording/reproducing speed decreases, making it difficult to continuously record/reproduce at a constant speed.

[Means for Solving the Problems (and Effects)] According to the present invention, since recording and reproduction are performed by applying a voltage to the recording medium while moving the probe electrode for recording and reproduction in a circular motion, the probe electrode is moved during linear reciprocating motion. It is possible to eliminate vibrations that occur when the electrodes are reversed, and it is possible to eliminate noise components caused by this vibration. Furthermore, since the probe electrode can be operated at a constant speed, it is also possible to record and reproduce continuously at a constant speed.

In other words, the present invention is characterized by having a probe electrode and a recording medium having an electric memory effect, and recording and reproducing in a concentric or spiral manner by applying a voltage to the recording medium while moving the probe electrode in a circular manner. The purpose of the present invention is to provide a recording and reproducing device that can perform

[Detailed description of aspects of the invention]

The recording medium used in the present invention is an organic cumulative film in which molecules having both a group with a π electron level and a group with only an electron level are stacked on an electrode, and a probe electrode is used in a direction perpendicular to the film surface. By flowing current, it is possible to exhibit nonlinear current-voltage characteristics that are different from conventional ones.

Since most organic materials generally exhibit insulating or semi-insulating properties, there is a wide variety of organic materials having a group having a π-electron level that can be applied to the present invention.

Examples of structures of dyes having a π-electron system suitable for the present invention include phthalocyanine, dyes having a porphyrin skeleton such as tetraphenylporphine, azulene dyes having squarylium groups and croconic methine groups as bonding chains, and quinoline.

Cyanine-based similar dyes in which two nitrogen-containing heterocycles such as benzothiazole and benzoxazole are bonded through squarylium groups and croconic methine groups, or cyanine dyes, fused polysensitive aromatics such as anthracene and pyrene, and aromatic rings and Chain compounds of polymerized heterocyclic compounds and polymers of diacetylene groups, derivatives of tetraquinodimethane or tetrathiafulvalene, their analogs and charge transfer complexes thereof, and metals such as ferrocene and trisbipyridine ruthenium complexes. Examples include complex compounds.

Examples of polymeric materials suitable for the present invention include addition polymers such as polyacrylic acid derivatives, condensation polymers such as polyimide, ring-opening polymers such as nylon, and biopolymers such as bacteriorhodopsin.

Regarding the formation of an organic recording medium, it is possible to specifically apply the vapor deposition method, the Kleister ion beam method, etc., but the LB method is extremely suitable among the known conventional techniques due to its controllability, ease, and reproducibility. It is.

According to this LB method, a monomolecular film of an organic compound having a hydrophobic site and a hydrophilic site in one molecule or a cumulative film thereof can be easily formed on a substrate, and has a thickness on the order of a molecule. , and can stably supply a uniform and homogeneous ultra-thin organic film over a large area.

The LB method is a molecule with a structure that has a hydrophilic site and a hydrophobic site, and when the balance between the two (amphiphilic balance) is maintained appropriately, the molecule lowers the hydrophilic group on the water surface. This is a method of producing a monomolecular film or a cumulative film thereof by utilizing the fact that it becomes a monomolecular layer toward.

Examples of the group constituting the hydrophobic moiety include various hydrophobic groups such as generally widely known saturated and unsaturated hydrocarbon groups, fused polycyclic aromatic groups, and chain polycyclic phenyl groups. These each constitute a hydrophobic site singly or in combination. On the other hand, the most typical constituent elements of the hydrophilic moiety are, for example, carboxyl groups, ester groups, and acid amide groups.

Imide groups, hydroxyl groups, and even amino groups (1°2.
Examples include hydrophilic groups such as tertiary and quaternary).

These also constitute the hydrophilic portion of the above molecule either singly or in combination.

If it has both these hydrophobic groups and hydrophilic groups in a well-balanced manner, it is possible to form a monomolecular film on the water surface.
This is an extremely suitable material for the present invention.

Specific examples include the following molecules.

<Organic materials> [11 Croconic methine dye [11] A compound in which the croconic methine group of the compound listed in squarylium dye [I] is replaced with a squarylium group having the following structure.

[III 1 Porphyrin dye compound Here, R corresponds to the group having the above-mentioned σ electron level, and is a long-chain alkyl group introduced to facilitate the formation of a monomolecular film on the water surface. The number of carbon atoms n is 5<n<
30 is preferred.

Rare earth metal ion [Tv co-fused polycyclic aromatic compound (CH2) OOH Br- R is introduced to form a monomolecular film, and is not limited to the substituents listed here.

In addition, R1-R4,R are in the group with the above-mentioned σ electron level [
V] Diacetylene compound CH3 (-CH2 arrow.

CmiC-(,:C(-CH2),X 0≦n.

! ≦-20 However, n+1 〉 O X is a hydrophilic group, and 100OH is generally used, but -O
H.

-CONH2 etc. can also be used.

[VI] others Ku organic polymer materials 〉 6) Vinyl acetate copolymer [I] Addition polymer 1) Polyacrylic acid R.

polyacrylic acid ester polyimide Co2R.

Acrylic acid copolymer Acrylic acid ester copolymer ÷ 0CO-CH-CH2 ÷ Polyvinyl acetate [m] Ring-opening polymer l) Polyethylene oxide ÷ 0-CH-CH2 ± Sushi Sushi 1"i3 Here, R1 is the monomolecular film on the water surface A long-chain alkyl group introduced to facilitate the formation of a carbon number n of 5≦
It is preferable that n≦30.

Further, R5 is a short-chain alkyl group, and the number of carbon atoms n is 1≦n
≦4 is suitable. The degree of polymerization m is preferably 100≦m≦5000.

The compounds mentioned above as specific examples are only basic structures, and it goes without saying that various substituted products of these compounds are also suitable in the present invention.

In addition, organic materials other than those mentioned above are also suitable for the LB method.

Needless to say, any organic polymer material is suitable for the present invention. For example, biomaterials (eg, batatteriorhodobuscin and cytochrome C) and synthetic polypeptides (PBLG, etc.), which have been actively studied in recent years, can also be applied.

Such amphiphilic molecules form a monomolecular layer on the water surface with the hydrophilic groups facing downward. At this time, the monomolecular layer on the water surface has the characteristics of a two-dimensional system, and when the molecules are sparsely spread, there is a two-dimensional ideal gas between the area A per molecule and the surface pressure π. The formula π A=kT holds true, resulting in a "gas film". Here, k is Boltzmann's constant and T is absolute temperature. If A is made sufficiently small, the intermolecular interaction becomes stronger, resulting in a two-dimensional solid "condensation film (or solid film)." The condensed film can be transferred layer by layer onto the surface of arbitrary objects having various materials and shapes, such as glass and resin. Using this method, a monomolecular film or a cumulative film thereof can be formed and used as a recording layer.

As a specific manufacturing method, for example, the method shown below can be mentioned.

Chloroform and benzene for the desired organic compound.

Dissolve in a solvent such as acetonitrile. Next, using a suitable apparatus as shown in FIG. 7 of the accompanying drawings, the solution is spread on the aqueous phase 81 to form an organic compound in the form of a film.

Next, a partition plate (or float) 83 is provided to prevent this spread layer 82 from freely diffusing and spreading too much on the aqueous phase 81.
The expanded area of the expanded membrane 82 is limited to control the aggregated state of the membrane material, and a surface pressure π proportional to the aggregated state is obtained. By moving the partition plate 83, the developed area can be reduced to control the aggregation state of the membrane material, and the surface pressure can be gradually increased to set the surface pressure π suitable for membrane production. While maintaining this surface pressure, the monomolecular film of the organic compound is transferred onto the substrate 84 by gently raising or lowering the clean substrate 84 vertically. Such a monomolecular film 91 is a film in which molecules are arranged in an orderly manner, as schematically shown in FIG. 8a or 8b.

The monomolecular film 91 is manufactured as described above, and by repeating the above operations, a desired number of cumulative films can be formed. To transfer the monomolecular film 91 onto the substrate 84, in addition to the above-mentioned vertical dipping method, methods such as a horizontal adhesion method and a rotating cylinder method can also be used. The horizontal deposition method is a method in which a monomolecular film is transferred by bringing the substrate into horizontal contact with the water surface, and the rotating cylinder method is a method in which a cylindrical substrate is rotated above the water surface to transfer the monomolecular film onto the substrate surface. It's a method.

In the vertical immersion method described above, when a substrate with a hydrophilic surface is lifted out of water in a direction across the water surface, a monomolecular film 91 of an organic compound with the hydrophilic portion 92 of the organic compound facing the substrate 84 is formed on the substrate 84. (Fig. 8b). When the substrate 84 is moved up and down as described above, the monomolecular films 91 are stacked one by one in each step, forming a cumulative film 101.

Since the direction of the film-forming molecules is reversed during the pulling process and the dipping process,
According to this method, a Y-shaped film is formed between each layer of the monomolecular film in which the hydrophobic sites 93ii and 93b of the organic compound face each other (FIG. 9a). On the other hand, in the horizontal deposition method, a monomolecular film 91 with the hydrophobic portion 93 of the organic compound facing the substrate 84 side is used.
is formed on substrate 84 (FIG. 8a). In this method, even if the monomolecular film 91 is accumulated, the direction of the film-forming molecules does not change, and an X-shaped film is formed in which the hydrophobic parts 93a and 93b face the substrate 84 in all layers (No. 9b figure). On the other hand, the cumulative film 101 in which the hydrophilic portions 92a and 92b of all the layers face the substrate 84 is called a type 2 film (FIG. 9C).

The method of transferring the monomolecular film 91 onto the substrate 84 is not limited to the above method, and when a large-area substrate is used, a method of extruding the substrate from a roll into an aqueous phase may also be adopted. Further, the directions of the hydrophilic groups and hydrophobic groups described above toward the substrate are in principle, and can be changed by surface treatment of the substrate, etc.

As described above, a potential barrier layer consisting of the organic compound monomolecular film 91 or its cumulative film 101 is formed on the substrate 84.

In the present invention, the substrate 84 for supporting the thin film in which the above-mentioned inorganic and organic materials are laminated may be metal, glass,
Any material such as ceramics or plastic material may be used, and biomaterials with extremely low heat resistance may also be used.

The substrate 84 as described above may have any shape (preferably a flat plate, but is not limited to a flat plate at all).

That is, the above film forming method has the advantage that a film can be formed in accordance with the shape of the surface of the substrate, no matter what shape it is.

On the other hand, the electrode material used in the present invention may be any material as long as it has high conductivity (for example, Au, Pt, etc.).

There are many materials, including metals such as Ag, Pd, Af, In, Sn, Pb, and W, and their alloys, as well as graphite, silicide, and even conductive oxides such as ITO. can be applied to the present invention.As a method for forming electrodes using such materials, conventionally known thin film techniques are sufficient.However, when electrode materials are formed directly on a substrate, the surface is It is preferable to use a conductive material that does not form an insulating oxide film, such as a noble metal or an oxide conductor such as ITO.

Note that the metal electrode of the recording medium is necessary because the recording layer of the present invention is insulative, but if the recording layer exhibits semiconductor properties of MΩ or less, the metal electrode is unnecessary.

That is, the recording layer itself can be used as a counter electrode to the probe electrode.

Further, the tip of the probe electrode needs to be as sharp as possible in order to improve recording/reproducing/erasing resolution. In the present invention, a probe is used in which Si is implanted onto a SiO□ substrate using a focused ion beam, St is selectively grown on the Si, and Au is evaporated to make it conductive. However, the shape of the probe and the processing method are not limited thereto.

When an element with the MIM structure shown in FIG. 4 is created using the materials and film formation method described above, a memory switching element exhibiting current-voltage characteristics as shown in FIGS. 5 and 6 is obtained. It has already been found that two states (ON state and OFF state) each have memory properties. These memory switching characteristics range from several λ to several 1,
However, as a recording medium in the present invention, a layer thickness in the range of several Å to 500 layers is preferable (most preferably one with a layer thickness in the range of lOλ to 200 layers). is good.

In FIG. 4, reference numeral 84 represents a substrate, 41 an Au electrode, 42 an Ai electrode, and 43 the aforementioned monomolecular cumulative film.

FIG. 1 is a block diagram showing a recording/reproducing apparatus of the present invention. In Fig. 1, 105 is a probe current amplifier;
06 is a servo circuit that controls the fine movement mechanism 107 using a piezoelectric element so that the probe current becomes constant, that is, the distance between the recording layer 101 and the probe electrode 102 is kept constant. 108 is the probe electrode 102 and the substrate electrode 10
This is a power supply for applying a pulse voltage for recording/erasing to the recording layer 101 between 3 and 3.

Since the probe current changes rapidly when applying the pulse voltage, the servo circuit 106 controls the HOLD circuit to be turned on so that the output voltage remains constant during that time.

110 and 111 are used to coarsely control the distance between the probe electrode 102 and the recording medium 101 so that a probe current of about 10-'A is obtained in advance.

109 is an xY scan drive circuit for controlling the movement of the probe electrode 102 in the XY force directions. In the present invention, the voltages Vx and V applied for scanning drive in the X direction and the Y direction are
By adjusting the magnitude and phase of y, the probe electrode 102 is controlled to move circularly.

Each of these devices is all controlled by a microcomputer 112.
Centrally controlled by Further, 113 represents a display device.

Furthermore, the mechanical bending performance in movement control using piezoelectric elements is shown below.

Z direction fine movement control range: 0. lnm-1 μm Z-direction coarse movement control range: 10 nm to 10 mm XY-direction scanning range: 0.1 layer m to I p m Measurement/control tolerance: <0.1 layer m or less The present invention will be described according to examples.

[Example 1] A recording and reproducing apparatus shown in FIG. 1 was used. Probe electrode 10
As No. 2, a platinum/rhodium probe electrode was used. The distance between this probe electrode 102 and the surface of the recording layer 101 (
The distance (Z) is controlled by a piezoelectric element to keep the current constant.

Furthermore, the fine movement control mechanism 107 keeps the distance Z constant,
It is designed to allow fine movement control in the in-plane (x, y) directions as well.

FIG. 2a shows a fine movement control mechanism 107 and a probe electrode 102,
A schematic diagram of a recording medium is shown. The fine movement control mechanism 107 has a cylindrical piezoelectric element and electrodes for applying fine movement control voltages in the X direction, Y direction, and Z direction.
By applying voltage to +X and -X as shown in the figure,
It is possible to scan in the direction.

Further, the probe electrode 102 can directly perform recording, reproduction, and erasing. In addition, the recording medium is a high-precision xy stage 1
14 and can be moved to any position.

Next, squaryryum bis-6-year-old thylazulene (hereinafter 5O
The details of the recording/reproducing/erasing experiment using the LB film (8 layers) of AZ (abbreviated as AZ) are described below.

Recording medium 1 having a recording layer 101 in which 5 OAZ 8 layers are accumulated
was placed on the XY stage 114, and the position of the probe electrode 102 was first determined visually and firmly fixed. A
+3. between u electrode (earth side) 1o3 and probe electrode 102. A voltage of OV was applied, and the distance (Z) between the probe electrode 102 and the surface of the recording layer 101 was adjusted while monitoring the current. At this time, the probe electrode 102 and the recording layer 101
The probe current 1p for controlling the distance Z to the surface is 1
It was set so that O-IIA≧Ip≧10A. 1, which is a voltage that does not exceed a threshold voltage that causes an electrical memory effect between the probe electrode 102 and the Au electrode 103;
When a reading voltage of 5V was applied and the current value was measured, an OFF state was indicated at less than μA. Next, after applying a triangular wave pulse voltage having the waveform shown in Figure 3, which is a voltage higher than the threshold voltage Vth that causes an ON state, a voltage of 1.5 V was applied between the electrodes again and the current was measured. However, a current of about 0.7 mA flowed, indicating that it was in an ON state. That is, an ON state was recorded.

Next, the threshold voltage Vth that changes from the ON state to the OFF state
, peak voltage 5V that is higher than OFF, pulse width 1
After applying a triangular wave pulse voltage of μs, 1.5V is applied again.
When applied, the current value at this time is OFF below μ
It was confirmed that the condition has returned.

The X direction and Y direction of the fine movement control mechanism 107 shown in FIG. 2a
A voltage Vx is applied to the electrodes in each direction from the XY scan drive circuit
Vy is applied to move the probe electrode 102. The applied voltages Vx and Vy at this time are shown below.

By applying the above voltage to the cylindrical piezoelectric element, the probe electrode is moved in a spiral shape, and a triangular wave pulse voltage is applied between the probe electrode and the Au electrode in the above-described manner to obtain o, ooiμm NO, 1μm The ON state was written at various pitches in between, and continuous data was recorded in a spiral pattern.

Next, during recording, the distance between the probe electrode and the Au electrode was 1.5 mm, while the probe electrode was moved in a spiral manner.
When reproducing was performed by applying a voltage of 0.01 μm
Data signals could be read out continuously at a constant speed with the following resolution: Further, in this experiment, noise caused by vibration, which was observed when recording and reproducing by moving the probe electrode back and forth linearly in the X direction or the Y direction, was not observed.

The 5OAZ-LB film used in the above experiment was prepared as follows.

After cleaning the optically polished glass substrate (substrate 104) using a neutral detergent and Triclean, Cr was applied as an undercoat layer.
A base electrode (Au electrode 103) was made by depositing Au to a thickness of 50 layers using the vacuum evaporation method, and then depositing 400 layers of Au using the same method.
was formed.

Next, a chloroform solution in which 5OAZ was dissolved at a concentration of 0.2 mg/ml was spread on the water phase at 20°C to form a monomolecular film on the water surface. Waiting for the evaporation of the solvent, the surface pressure of the monomolecular film was increased to 20 mN/m, and while keeping this constant, the electrode substrate was moved across the water surface at a speed of 5 mm 7
The film was gently immersed for 1 minute, and then pulled up to accumulate two Y-shaped monolayers. By repeating this operation an appropriate number of times, six types of cumulative films of 2.4.8°12 and 20.30 layers were formed on the substrate, and recording and reproducing experiments were conducted. The evaluation results are shown in Table 1.

The evaluation is comprehensively judged based on the quality of recording and erasing properties after applying the recording write pulse and erasing voltage, as well as the ratio of current values in the recording state and erasing state (ON10FF ratio) and resolution. ◎、Good item ○
, Items with somewhat lower ratings compared to others were marked △.

[Example 2] In place of the 5OAZ recording medium used in Example 1, lutetium siphthalodianine [LuH(Pc) 2 ]]t-
An experiment was conducted in the same manner as in Example 1 except that butyl induction was used. The results of recording performance, 0N10FF ratio, erasability, and resolution are summarized in Table 1. Similar to 5OAZ, data signals could be recorded and reproduced continuously at a constant speed, no noise due to vibration was observed, and a signal with a good S/N ratio was obtained.

Note that the accumulation conditions for the t-butyl derivative of LuH(Pc)2 are as follows.

Solvent: Chloroform/trimethylbenzene/acetone (1/1/2) Concentration: 0.5mg/mI! Water phase: pure, water temperature 20℃, surface pressure: 20 mN/m, substrate vertical speed 3
m m /Publication 1 [Example 3] Similar to Example 1, the recording/reproducing device shown in FIG. 1 having the fine movement control mechanism 107 consisting of a cylindrical piezoelectric element shown in FIG. 8 layers) as a recording medium.

The fine movement control voltage applied to the cylindrical piezoelectric element is shown below.

However, ω: angular velocity, v (B: voltage amplitude, C and D are constants, and Int (x) indicates the integer part of X.

Recording and reproducing experiments were conducted in the same manner as in Example 1 while the probe electrodes were operated in concentric circles by applying the above voltage, and results almost the same as in Example 1 were obtained.

Although the embodiment has been described using a cylindrical piezoelectric element as the fine movement control mechanism 107, the present invention is not limited to this. For example, a parallel hinge spring or the like may be used, and the fine movement control mechanism 107 can be controlled in the XY force direction. It's fine as long as it's possible.

〔Effect of the invention〕

As explained above, by performing recording and reproducing by applying a voltage to the recording medium while moving the probe electrode for recording and reproducing in a circular motion, it is possible to eliminate the vibration that occurs when the probe electrode is reversed during reciprocating linear motion. Since noise components due to vibration can be eliminated and the probe electrode can be operated at a constant speed, it is also possible to record and reproduce continuously at a constant speed.

[Brief explanation of drawings]

FIG. 1 is a diagram of a recording/reproducing apparatus used in the present invention. FIGS. 2a and 2b are a schematic diagram and a scanning explanatory diagram of the fine movement control mechanism. FIG. 3 shows the recording signal waveform. FIG. 4 is a schematic diagram of the structure of the MIM element, and FIGS. 5 and 6 are characteristic diagrams showing the electrical characteristics obtained with the element of FIG. 4. FIG. 7 is a schematic diagram of a cumulative film forming apparatus. Figures 8a and 8b are schematic diagrams of monolayers;
Figures 9b and 9c are schematic diagrams of cumulative films. 1...... Recording medium 101...
...... Recording layer 102...
......Probe electrode 103...
......Substrate electrode 104...
...... Board 105 ...... Probe current amplifier 106 ...... Servo circuit 107 ...... ...Fine movement control mechanism 1
08・・・・・・・・・・・・Pulse power supply 109・
......xY scan drive circuit 110...
......Coarse movement mechanism 111...
...... Coarse movement drive circuit 112 ...... Microcomputer 113 ......
・・Display device 114・・・・・・・・・XY stage 2nd stage 7

Claims (14)

[Claims] (1) A recording/reproducing device having a probe electrode, a recording medium having an electric memory effect, and a recording and/or reproducing means for applying a voltage from the probe electrode to the recording medium,
A recording/reproducing device further comprising a drive means for circularly moving the probe electrode. (2) The recording/reproducing apparatus according to claim 1, wherein the recording medium is arranged between the probe electrode and a counter electrode arranged opposite to the probe electrode. (3) The recording/reproducing apparatus according to claim 1, wherein the recording medium has a monomolecular film of an organic compound or a cumulative film formed by accumulating the monomolecular layers. (4) The thickness of the monomolecular film or cumulative film is from several angstroms to several hundred
4. The recording/reproducing apparatus according to claim 3, wherein the recording/reproducing device has a range of 0 Å. (5) The thickness of the monomolecular film or cumulative film is several Å to 500 Å
4. The recording/reproducing apparatus according to claim 3, wherein the recording/reproducing apparatus is within the range of . (6) The thickness of the monomolecular film or cumulative film is 10 Å to 200 Å.
4. The recording/reproducing apparatus according to claim 3, wherein the recording/reproducing apparatus has a range of .ANG. (7) The recording/reproducing device according to claim 3, wherein the monomolecular film or the cumulative film is a film formed by an LB method. (8) The recording/reproducing device according to claim 3, wherein the organic compound has a group having a π electron level and a group having a σ electron level in the molecule. (9) Claim 1, wherein the organic compound is an organic dye compound.
The recording/playback device described. (10) The organic compound is a dye having a porphyrin skeleton, an azulene dye, a cyanine dye, a dye having a squarylium group, a dye having a croconic methine group, a fused polycyclic aromatic compound, a fused heterocyclic compound, a diacetylene polymer. At least one compound selected from the group consisting of tetraquinodimethane, tetrathiafulvalene, and metal complex compounds.
4. The recording/reproducing device according to claim 3, wherein the recording/reproducing device is a seed compound. (11) The recording/reproducing apparatus according to claim 1, further comprising an XY scanning drive device for circularly moving the probe electrode. (12) The recording/reproducing apparatus according to claim 1, further comprising means for finely controlling the relative position of the probe electrode and the recording medium in three dimensions. (13) Write to a recording medium that has an electric memory effect by applying a voltage that exceeds the threshold voltage that causes the electric memory effect from the probe electrode, or apply a voltage that does not exceed the threshold voltage that causes the electric memory effect. A recording/reproducing method for reading changes in the amount of current flowing through the recording medium, further comprising the step of circularly moving the probe electrode when writing or reading. (14) The recording/reproducing method according to claim 13, wherein the circular movement is concentric or spiral movement.