Abstract: The field of this disclosure is making three-dimensional topographic structures by means of graduated exposure in a photosensitive material, such as a photoresist, photosensitive polymide, or similar. Such patterns may be written either to be used directly as optical, mechanical, fluidic, etc. components, e.g. diffusors, non-reflecting surfaces, Fresnel lenses and Fresnel prisms, computer-generated holograms, lenslet arrays, etc, or to be used as masters for the fabrication of such components by replication. Replication can be done by molding, pressing, embossing, electroplating, etching, as known in the art. This disclosure includes descriptions of using passive absorbing components in thin resist, using high gamma thick resists with high resolution pattern generators, using multiple focal planes including at least one focal plane in the bottom half of the resist, and iterative simulation of patterning and adjustment of an exposure map.

Abstract: The field of this disclosure is making three-dimensional topographic structures by means of graduated exposure in a photosensitive material, such as a photoresist, photosensitive polymide, or similar. Such patterns may be written either to be used directly as optical, mechanical, fluidic, etc. components, e.g. diffusors, non-reflecting surfaces, Fresnel lenses and Fresnel prisms, computer-generated holograms, lenslet arrays, etc, or to be used as masters for the fabrication of such components by replication. Replication can be done by molding, pressing, embossing, electroplating, etching, as known in the art. This disclosure includes descriptions of using passive absorbing components in thin resist, using high gamma thick resists with high resolution pattern generators, using multiple focal planes including at least one focal plane in the bottom half of the resist, and iterative simulation of patterning and adjustment of an exposure map.

Abstract: A compound having, in its molecule, a polymethine chain structure containing a partial structure represented by the following formula (1-1), and an image forming material containing the same. In the formula (1-1), R1, R2, R3, R4, and X each independently represent a hydrogen atom, a halogen atom, or a monovalent organic group. The image forming material is useful as the image recording layer of a planographic printing plate precursor.

Abstract: A positive type resist composition for use in liquid immersion exposure comprises: (A) a resin having a monocyclic or polycyclic cycloaliphatic hydrocarbon structure, the resin increasing its solubility in an alkali developer by an action of acid; (B) a compound generating acid upon irradiation with one of an actinic ray and a radiation; (C) an alkali soluble compound having an alkyl group of 5 or more carbon atoms; and (D) a solvent.

Abstract: Provided are methods of applying a tissue marking to a tissue and rendering said tissue marking colorless when desired, comprising implanting into the tissue an amount of the tissue marking in sufficient quantity to form a detectable marking, said tissue marking comprising at least one colored compound comprising a thermally activatable fragmentation group and at least one infrared absorbing compound, wherein the at least one colored compound is capable of being rendered colorless by unimolecular fragmentation of the thermally activatable fragmentation group when the tissue marking is non-imagewise exposed by a source of infrared radiation and applying sufficient infrared radiation to a sufficient amount of the tissue marking to render the tissue marking colorless when desired.

Abstract: An exposure system includes an exposure section for irradiating a formed resist film with exposing light through a mask with an immersion liquid provided on the resist film, and a drying section for drying a surface of the resist film after irradiation.

Abstract: Disclosed is to provide with an optical recording medium of a write-once type in which an excellent recording characteristic can be obtained over low speed recording to high speed recording.

Abstract: The present invention relates to a photosensitive resin composition excellent in pliability, ultraviolet sensitivity for development, developability with an aqueous alkali solution, and storage stability at room temperature and a circuit substrate employing the same. The photosensitive resin composition includes a siloxane-containing polyamic acid resin having structural units respectively represented by the following formulae (1), (2), and (3) and a photopolymerization initiator incorporated therein. The circuit substrate is coated with the photosensitive resin composition.

Abstract: The present invention is directed to a film forming, photoactive, homogeneously mixed material comprising a complex prepared from (a) at least one ionic photosensitive compound which may undergo a photoreaction, selected from photoisomerizations, photocycloadditions and photoinduced rearrangements, and/or (a?) at least one photosensitive polyelectrolyte (“second polyelectrolyte”) carrying residues which may undergo said photoreaction, and (b) at least one (“first”) polyelectrolyte carrying charges which are opposite to those of the active groups of the photosensitive material. This material has unique photochemical properties in that non-scattering, optically clear films may prepared therefrom which allow light-induced generation of optical anisotropy and of topological surface structures, e.g. such as surface relief gratings (SRG).

Abstract: Composition, which comprises a latent activator and a colour former, a process for the preparation of these compositions, substrates coated with these compositions and a process for their preparation, a process for preparing marked substrates using these compositions and marked substrates obtainable by the latter process.

Abstract: Polymers comprising a first methacrylate monomer having a pendent spacer between the polymer backbone and an acid-liable acetal group, a second methacrylate monomer having a pendent group including a fluorinated alkyl group and a third methacrylate monomer having a pendent hydrocarbon group. Photoresist formulations include the polymers, a photoacid generator and a casting solvent. Methods of patterning photoresist films formed from the photoresist formulations are characterized by post-exposure bakes at temperatures of about 60° C. or less.

Abstract: A method for manufacturing a lens forming master includes coating an organic insulation material on a substrate to form an organic insulation layer, removing a portion of the organic insulation layer with a laser which is irradiated through a first mask to form a lens shape on a surface of the organic insulation layer, and removing portions of the organic insulation layer with a laser irradiated through a second mask to form a contact hole and a bank area in the organic insulation layer.

Abstract: A photosensitive composition comprises: (A) a compound capable of generating an acid represented by formula (I) upon irradiation with actinic ray or radiation; and (B) a resin that decomposes by the action of an acid to its increase solubility in an alkali developer wherein Ra represents an alkyl group substituted with a fluorine atom, or an aryl group substituted with a fluorine atom or a group having a fluorine atom; Rb represents an alkyl group not substituted with a fluorine atom on ?-position of the alkyl group, or an aryl group not substituted with a fluorine atom or a group having a fluorine atom.

Abstract: A colorless or transparent composition comprises a charge-delocalization compound and a photoacid, wherein the photoacid generates an acid on irradiation or heating, thereby forming a colored change-transfer complex with said compound.

Abstract: The present invention provides a composition, which comprises a latent activator. It also provides a process for the preparation of these compositions, substrates coated with these compositions and a process for their preparation, a process for preparing marked substrates using these compositions and marked substrates obtainable by the latter process.

Abstract: A first resist film is formed on a substrate, and first pattern exposure is performed such that the first resist film is irradiated with exposure light through a first mask. Then, the first resist film is developed, thereby forming a first resist pattern out of the first resist film. Subsequently, a nano-carbon material is attached to the surface of the first resist pattern, and then a second resist film is formed on the substrate including the first resist pattern. Thereafter, second pattern exposure is performed such that the second resist film is irradiated with exposure light through a second mask. Then, the second resist film is developed, thereby forming a second resist pattern out of the second resist film.

Abstract: A photosensitive resin composition comprising: (A) a binder polymer; (B) a photopolymerizable compound that has an ethylenically unsaturated bond; and (C1) a compound represented by general formula (1) below, wherein, at least one R represents a C1-10 alkoxy group or a C1-12 alkyl group; the sum of a, b, and c is 1 to 6; and when the sum of a, b, and c is 2 to 6, each R may be the same as or different from one another.

Abstract: A fluorine-containing compound represented by a general formula (c-1) shown below: [Chemical Formula 1] RX-AN-(OR2)a??(c-1) [wherein, RX represents an organic group, AN represents a naphthalene ring that may have a substituent, R2 represents a base dissociable group, and a represents 1 or 2, provided that at least one among AN and said a R2 groups contains a fluorine atom].

Abstract: The azo-metal chelate dye to which the present invention is applied is a compound formed as follows: for example, 1,3,4-thiadiazole ring is selected as the diazo component; the diazo component is combined with a coupler component having condensed rings including a fluorine-substituted alkylsulfonylamino group and an amino group, to form an azo dye compound; and the azo dye compound forms chelate bonds with at least one metal selected from the group consisting of Co, Ni, Cu and Pd. Here, two absorption bands (OD1 and OD2) are seen in the absorption spectrum, which is measured in a range of 400 to 800 nm wavelengths. The azo-metal chelate dye is characterized in that the optical density ratio (OD2/OD1) of the two absorption bands is greater than 1.25. By using this azo-metal chelate dye, an optical recording medium capable of high-speed recording is provided.

Abstract: The present invention provides a solid material comprising an immobilized mixture of two or more proteorhodopsins, two or more bacteriorhodopsins, or one or more bacteriorhodopsin and one or more proteorhodopsins. The proteorhodopsins are selected from the group consisting of all-trans-retinal-containing proteorhodopsins and retinal analog-containing proteorhodopsins; all of which have absorption spectra that do not overlap. The bacteriorhodopsins are selected from the group consisting of all-trans-retinal-containing bacteriorhodopsins and retinal analog-containing bacteriorhodopsins; all of which have absorption spectra that do not overlap. The present invention also provides an optical information carrier, such as an optical data storage material and a fraud-proof optical data carrier, comprising the above-described solid material and a substrate selected from the group consisting of glass, paper, metal, fabric material, and plastic material, wherein said solid material is deposited on said substrate.

Abstract: An imaging method is disclosed. An imaging composition is coated on a work piece followed by applying a sufficient amount of energy from a 3-D imaging system to form an image on the coated work piece. The image may be a logo or marker for alignment of parts.

Abstract: In a process for recording into a rewritable recording medium of a non-contact type, when adjacent lines or adjacent overlapping lines are drawn by scanning the medium having a reversible heat sensitive color developing layer on a substrate with laser light and a second line 2 is drawn after a first line 1 is drawn, the time between the start of drawing 1 and the end of drawing 2 and/or the width of the overlapped portion r is controlled as the means for suppressing discoloration of the recorded lines by interference between heat remaining after 1 has been drawn and heat generated while 2 is drawn. When characters, bar codes, solid images or figures are drawn into a rewritable recording medium of the non-contact type by scanning with laser light, excellent readability and visibility of the bar codes can be obtained in recording a plurality of line elements.

Abstract: An optical data storage system and method with non-destructive multiple readout of 3-D data stored in multiple layers uses two-photon induced fluorescence modulation. The novel system uses the photochromic properties of the open and closed form of diarylethene in the two-photon energy transfer-based read-out method of a 3-D optical data storage system, providing more than 10,000 readout cycles without significantly compromising the stored data. The system of the present invention can be recorded and read out using the same wavelength simply by changing the intensities. Also, since the incident intensity used in two-photon readout is low due to the efficient absorption of the two-photon absorbing fluorene dye, a less expensive, nanosecond laser diode can be used, making this two-photon 3-D data storage system less expensive, stable, highly responsive, and reliable. This photochromic system is capable of either write-once read many (WORM) or erasable and rewritable 3D optical data storage.

Abstract: An organic electroluminescent display (OELD) device and a method of fabricating the same are disclosed. The OELD device includes a substrate, a first electrode, an organic layer containing at least one light emitting layer, and a second electrode. The light emitting layer is comprised of at least one phosphorescent dopant and at least two host materials.

Abstract: An optical information recording and reproducing device 1 irradiates initialization light L1 to an optical information recording medium 100 having a recording layer 101 made of photopolymerization-type photopolymer in advance to bring about the photopolymerization or the photocrosslinking to perform the initialization processing, and condenses a recording light beam L2c having a comparatively strong light intensity to a target position in the recording layer 101 and increases the temperature thereof to transubstantiate the target position to record a recording mark RM at the time of recording information, and condenses a reading light beam L2d having a comparatively weak light intensity to the target position and receives a returned light beam L3 having a sufficient light amount reflected by the recording mark RM at the time of reproducing information, which makes it possible to reliably record the recording mark RM and stably read out the recording mark RM.

Abstract: According to one embodiment, a write-once type information storage medium using a recording material which has a low to high characteristic that a light reflectivity in a recording mark increases with respect to a non-recording area and which has a recording characteristic in accordance with a principle of recording without substrate deformation, wherein the recording material includes at least an organic metal complex, and wherein the organic metal complex includes a center metal.

Abstract: The present invention provides a donor substrate used in forming a light emitting layer by forming a transfer layer containing light emission material, irradiating a radiation ray to the transfer layer while the transfer layer and a substrate to be transferred face each other, and sublimating or vaporizing the transfer layer so that the transfer layer is transferred to the substrate to be transferred. The donor substrate includes: a base; a photothermal conversion layer arranged on the base; and a heat interfering layer arranged between the base and the photothermal conversion layer, and including two or more layers with refraction index different from each other.

Abstract: Provided is a positive resist composition using a resin having, in the polymer main chain, a specific acid decomposable structure and further having, in the side chain thereof, several specific acid decomposable groups, satisfactory in an exposure latitude, a focus latitude, and pattern collapse prevention at a high level, and having reduced development defects; and a pattern forming method.

Abstract: An object is to provide a display device that can be manufactured with increased use efficiency of a material by a simplified manufacturing process and a manufacturing technique thereof. A light-absorbing layer is formed, an insulating layer is formed over the light-absorbing layer, the light-absorbing layer and the insulating layer are selectively irradiated with laser light, so that an irradiated region of the light-absorbing layer and an irradiated region of the insulating layer are removed, and accordingly an opening is formed in the light-absorbing layer and the insulating layer, and a conductive film is formed in the opening so as to be in contact with the light-absorbing film. The conductive film is formed in the opening so as to be in contact with the exposed light-absorbing layer, so that the light-absorbing layer and the conductive film are electrically connected to each other with the insulating layer interposed therebetween.

Abstract: A reusable image forming medium, including a substrate; an imaging layer coated on or impregnated into the substrate, wherein an irradiation of the imaging layer produces an image; and a signature material coated on or impregnated into the substrate or the imaging layer, the signature material being detectable by a sensor.

Abstract: An optical recording medium includes a substrate and a plurality of recording layers laminated via at least intermediate layers, at least one of the recording layers other than a recording layer farthest from a light incidence plane among the plurality of recording layers containing at least one metal M selected from a group consisting of Ni, Cu, Si, Ti, Ge, Zr, Nb, Mo, In, Sn, W, Pb, Bi, Zn and La and an element X which can combine with the metal M upon being irradiated with a laser beam for recording data, thereby forming a crystal of a compound of the element X with the metal M. According to the thus constituted optical recording medium, it is possible to record data in and reproduce from a farthest recording layer from a light incidence plane in a desired manner and it is possible to record data in and reproduce from recording layer(s) other than the farthest recording layer from the light incidence plane in a desired manner.

Abstract: The invention provides a composition having laser engraving properties, comprising a host material and an effective amount of a laser enhancing additive. The laser enhancing additive comprises a first quantity of least one of copper potassium iodide (CuKI3) or Copper Iodide (CuI), and a second quantity at least one substance selected from the group consisting of zinc sulfide (ZnS), barium sulfide (BaS), alkyl sulfonate, and thioester. The composition can be engraved with grayscale images by an Nd:Yag laser and can be added to laminates or coatings. The composition can be used during the manufacture of many articles of manufacture, including identification documents.

Abstract: A positive resist composition comprising (A) a resin which contains all of the repeating units represented by formulae (I) to (III), and becomes soluble in an alkali developer by the action of an acid, and (B) a compound capable of generating an acid upon irradiation with an actinic ray or radiation; and a pattern forming method using the composition. A represents a group capable of decomposing and leaving by the action of an acid, each R1 independently represents hydrogen or a methyl group, R2 represents a phenyl group or a cyclohexyl group, m represents 1 or 2, and n represents an integer of 0 to 2. By virtue of this construction, a resist composition ensuring high resolution, good pattern profile, sufficient depth of focus, little defects after development, and sufficiently high plasma etching resistance is provided.

Abstract: The field of this disclosure is making three-dimensional topographic structures by means of graduated exposure in a photosensitive material, such as a photoresist, photosensitive polymide, or similar. Such patterns may be written either to be used directly as optical, mechanical, fluidic, etc. components, e.g. diffusors, non-reflecting surfaces, Fresnel lenses and Fresnel prisms, computer-generated holograms, lenslet arrays, etc, or to be used as masters for the fabrication of such components by replication. Replication can be done by molding, pressing, embossing, electroplating, etching, as known in the art. This disclosure includes descriptions of using passive absorbing components in thin resist, using high gamma thick resists with high resolution pattern generators, using multiple focal planes including at least one focal plane in the bottom half of the resist, and iterative simulation of patterning and adjustment of an exposure map.

Abstract: A resist composition for immersion exposure including a base component (A) which exhibits changed solubility in an alkali developing solution under action of acid, an acid-generator component (B) which generates acid upon irradiation, and a fluorine-containing compound (C) having a group represented by general formula (c) shown below and containing at least one fluorine atom: wherein Q represents a group in which one hydrogen atom has been removed from a monovalent hydrophilic group; and R1 represents a hydrocarbon group of 2 or more carbon atoms which may have a fluorine atom.

Abstract: According to one embodiment, a write-once type information storage medium comprises a recording layer which is formed by mixing a plurality of organic dye based recording materials whose molecular weights are different from each other, and wherein a mixture ratio of organic dye based recording materials whose molecular weight is small is larger than a mixture ratio of organic dye based recording materials whose molecular weight is large.

Abstract: The present invention relates to thermoplastic material comprising polymer and at least one polychromic substance, wherein the polychromic substance is a functionalised diacetylene having the formula which has the general structure: X—C?C—C?C—Y—(CO)n-QZ wherein X is H or alkyl, Y is a divalent alkylene group, Q is O, S or NR, R is H or alkyl, and Z is alkyl, and n is 0 or 1. The present invention further relates to a method of processing thermoplastic material to form a plastic article, wherein the method comprises the step of processing the thermoplastic material at a temperature greater than the melt temperature of the thermoplastic, wherein the thermoplastic material comprises polymer and at least one polychromic substance as defined above; and further comprising the step of irradiating the plastic article to colour at least a region of the plastic article.

Abstract: The invention relates to a storage medium for storing information/data, wherein the storage medium comprises a dielectric storage material, more particularly a disk-shaped storage material on which a metal ion donor medium is arranged or can be applied on at least one side thereof. Metal ions can be transferred from the donor medium into the storage medium by exposing the storage medium to radiation, more particularly to laser radiation. The invention also relates to a storage medium for storing information/data, wherein the storage medium comprises a dielectric storage material, more particularly a disk-shaped storage material having at least one local metal ion doping, wherein the metal ions can be converted into metal particles and/or metal particles agglomerations by means of radiation, more particularly laser radiation.

Abstract: To provide an optical information recording medium including a pigment appropriate for high-density and high-speed optical recording by the blue laser light of 350 to 500 nm and especially around 400 nm (for example, 405 nm), enabling recording at low power, suppressing thermal affect of recording to the optical recording layer, and assuring a reflection ratio or modulation degree by the change of a refraction index n and an attenuation coefficient k; and to provide a recording method thereof. Instead of the recording based on the optical phase difference obtained by a change ?n of the refraction index n of the pigment as in the conventional method, a pigment capable of performing recording based on the change ?k of the attenuation coefficient k has been obtained. Recording may be performed mainly by the change ?k of the attenuation coefficient k.

Abstract: A resist composition and a method of forming a resist pattern that enable contamination within the exposure apparatus to be prevented in lithography processes using an electron beam or EUV (extreme ultraviolet light). In this method, an organic solvent containing, as the principal component, one or more compounds selected from a group consisting of propylene glycol monomethyl ether (PGME), methyl amyl ketone (MAK), butyl acetate (BuOAc), and 3-methyl methoxy propionate (MMP) is used as the resist solvent.

Abstract: Compositions comprising photobleachable organic materials can be bleached by 193 nm light, and brought back to their original state by stimuli after exposure. (reversible photobleaching). We use these compositions in art-known contrast enhancement layers and as a part of a photoresist, especially in optical lithography processes for semiconductor fabrication. They may comprise polymers such as organo-silicon polymers, polymers comprising polymers of aromatic hydroxyl compounds such as phenol and naphthol such as phenol formaldehyde polymers and naphthol formaldehyde polymers styrene polymers and phenolic acrylate polymers or cyclic materials comprising: where the radicals “R” and “Y” represent organo, or substituted organo moieties, Structures I, II, and III represent basic organic skeletons and can be unsubstituted or substituted in any available position with any one or combinations of multiple substituents.

Abstract: A method of producing a security document or article including a substrate (100), which is transparent at least to visible light, and a diffractive optical microstructure (112). The method includes applying an opacifying layer (102) to at least one surface of the transparent substrate (100). An area of the opacifying layer (102) is exposed to laser radiation (108) to ablate apertures (110) in selected portions of the opacifying layer (102), thereby forming a diffractive optical microstructure (112) on the surface of the substrate (100). The laser radiation may be patterned prior to exposing the opacifying layer (102), for example by passing the radiation through a mask (104). Alternatively, a focussed or collimated laser beam (206) may be directed onto the selected portions of the opacifying layer (102). Laser radiation may be directed onto the opacifying layer (102) either directly, or through the transparent substrate (100).

Abstract: A method of making micro-structure devices by coating a first layer of resist (12) on a substrate (10). A pattern is created on the substrate by radiation induced thermal removal of the resist.

Abstract: An information recording medium includes a substrate and an information layer formed on the substrate. The information layer includes a recording layer whose phase can be changed between a crystalline phase and an amorphous phase by irradiation with a laser beam or application of electric energy; a Cr-containing layer including at least Cr and O, arranged in contact with a first surface of the recording layer; and a Ga-containing layer including at least Ga and O, arranged in contact with a second surface of the recording layer.

Abstract: Record material imageable with a laser beam. The material is a substrate such as paper or polyolefin film having provided on at least one surface thereof a coating containing a solvent-soluble or disperse-type dye suitable for coloring plastics or polymers. Typical solvent-soluble and disperse-type dye include monoazo dyes, diazo dyes, anthraquinone dyes, coumarin dyes, quinoline dyes, xanthene dyes, and naphthalimide dyes. The record material does not show visible dye specks in the coating layer on the substrate because the dye has a very small average particle size—less than 50 microns. No more than 1% of the dye particles are larger than 100 microns. Also, method for imaging a substrate using heat energy by applying heat energy to the described record material to bring about a temperature in the coating greater than the melting temperature of the dye, causing color to become visible in the record material.

Abstract: A method of selectively removing a sacrificial material on a substrate is described. The method comprises forming a sacrificial layer on a substrate. Thereafter, the sacrificial layer is selectively decomposed at a temperature less than the temperature required to thermally decompose the sacrificial layer by selectively exposing the sacrificial layer to UV radiation.

Abstract: There are provided a polymer compound which can form a resist pattern with excellent resolution, and a negative resist composition containing the polymer compound and a resist pattern-forming method thereof. The present invention is a polymer compound containing a structural unit (a0) represented by a general formula (a0-1) shown below. (wherein, R represents a hydrogen atom, a halogen atom, an alkyl group or a halogenated alkyl group; and R0 represents an alkyl group containing a hydroxyl group.) Also, the present invention is a negative resist composition, including: an alkali soluble resin component (A), an acid generator component (B) that generates acid upon exposure, and a cross-linking agent (C), wherein the alkali soluble resin component (A) contains a polymer compound (A1) having a structural unit (a0) represented by the general formula (a0-1) shown above.

Abstract: A laser patterning apparatus for handling a donor film and improving compression uniformity between the donor film and an acceptor substrate is provided. The laser patterning apparatus includes: a stage that supports an acceptor substrate; a shielding mask that is placed on the acceptor substrate to form a pattern and is attached to a donor film on one surface thereof; a laser gun that is disposed at an upper part of the stage to radiate laser light to a portion of the donor film through the pattern of the shielding mask; a pressing member that corresponds to a portion of the shielding mask; and an actuator that is connected to one side of the pressing member to press the pressing member.

Abstract: A method of optimally setting exposure conditions when light emitted from an effective light source is applied to a mask pattern formed on a mask for exposure and diffracted light emitted from the mask is projected onto a substrate via a projection lens to expose the substrate thereto, the method comprising defining an image evaluation amount which represents characteristics of an optical image or a resist pattern and which contains a factor indicating the influence of a dimensional error of the mask pattern on the image characteristics, determining an initial condition of the effective light source and the mask pattern, defining at least one of a parameter of the effective light source and a parameter of the mask pattern, and changing at least one of the parameters to calculate the image evaluation amount, and deciding an optimum parameter on the basis of the result of the calculation.

Abstract: Phase-change type, reversible optical information recording medium, being possible for recording, reproducing, erasing, and rewriting of information, by use of a laser beam. This invention, consists of recording thin film of ternary elements, for example, containing Ge, Te, Sb/or Bi or quaternary elements containing the fourth element of Se with which a part of Te is replaced, which is established on such surface—flat substrates as glass or plastics. In this case, the component ratio of Te and Se is selected not to be excess for other elements, such as Ge, Sb/or Bi so as to be fixed as stable compounds of stoichiometric compositions of GeTe, Sb2Te3/or Bi2Te3, or GeSe, Sb2Se3/Bi2Se3 when crystallized. Strictly speaking, a concentration of each component is selected to have proper ratio of the number of atoms each other so as to represent whole composition as the sum of each component. By this treatment, it is possible to have high crystallization speed and long cyclability of recording/erasing.