Abstract: A tin-nickel alloy containing not less than 75 wt % and less than 100 wt % of tin with the balance of nickel. The alloy is used, for example, for formation of a surface treatment layer of an electronic component which is to be soldered onto a substrate with the use of the surface mount technology. The surface treatment layer preferably has a thickness of not less than 0.1 &mgr;m and less than 0.5 &mgr;m. The electronic component preferably further includes a nickel deposit layer as an underlying layer interposed between a base of the component and the surface treatment layer.

Abstract: A composite material for plain bearings comprises a backing layer, a bearing metal layer consisting of a copper alloy with a copper content of from 50 to 95 wt. % or an aluminum alloy with an aluminum content of from 60 to 95 wt. %, a diffusion barrier layer and an overlay, applied by electroplating, consisting of a lead-free, tin and copper-containing alloy. The invention provides a composite multilayer material whose overlay, applied by electroplating, does not exhibit any embrittlement even at relatively high temperatures, irrespective of the copper content. The overlay preferably comprises from 8 to 30 wt. % copper, 60 to 97 wt. % tin and 0.5-19 wt. % cobalt.

Abstract: There is provided a soldered article comprising a component having a Cu conductor joined with a solder, wherein the solder comprises about 0.1 to 2.0% by weight of Cu, about 1.0 to 7.5% by weight of Bi, and the balance being Sn. By using the above described lead-free solder, the occurrence of leaching is suppressed during soldering, and the solderability and joining strength can be improved. Since the solder does not contain Ag, material cost can be reduced, thus enabling reductions in the cost of the entire soldered article.

Abstract: Focusing and tracking can be stably performed using an optical information recording medium in which a high reflectivity and a large reflective change amount can be attained, and the reflectivity change amounts of the lands and grooves are set equal to each other by forming, between a transparent substrate and a first protective layer, an interference layer containing at least one material selected from the group consisting of Au, Ag, Cu, Si, and Ge. Even if information is recorded on the lands and the grooves, it can be recorded/reproduced without any crosstalk from an adjacent track.

Abstract: A description is given of a rewritable optical information medium having an IPIAIM stack comprising a phase-change recording layer sandwiched between two dielectric layers, a light-absorbing layer of a material like Si, Ge, Mo, or W, a third dielectric layer, and a metal mirror layer. The light-absorbing layer reduces the difference in light absorption between the amorphous state and the crystalline state to a minimum, thus reducing the recording mark distortion. The presence of the light-absorbing layer in this position ensures that the optical phase difference between the amorphous and the crystalline state is almost zero, making the medium suitable for land-groove recording.

Abstract: An information recording medium comprising a substrate having a recording surface provided with emboss pits or guiding grooves, a reflective film formed on the recording surface of the substrate, and a first protective film formed on the reflective film. This information recording medium is featured in that both sides of the information recording medium are constituted by a first surface provided with the protective film and by a second surface formed opposite to the first surface, and that an irradiated light beam is irradiated through the first surface, a recorded information being reproduced based on changes in light intensity of the reflected light beam. The distance between the recording surface of the substrate and the light incident surface is smaller than a thickness of the substrate, and a surface roughness "R" of the light incident surface meets a relationship represented by the following formula (1):R.ltoreq..lambda./(8n) (1)wherein .lambda.

Abstract: In a (Ge,Sb)-Te based optical recording medium of phase change type whose rate determining step in production has been initialization of the recording layer, the time required for production is reduced, and stable recording/reproducing properties are realized from the first overwriting operation. A phase-change type optical recording disc of write once read many-type requiring no initialization is also provided. The optical recording medium comprises a transparent substrate and a recording layer on the transparent substrate. The recording layer comprises at least one Te-based thin film and at least one reactive thin film, and the Te-based thin film is in contact with said reactive thin film. The Te-based thin film is formed from a Te-based material containing at least 95 at % of Te, and the reactive thin film is formed from a (Ge,Sb)-based material mainly comprising Ge and/or Sb. The optical change type material is formed by the mixing of the materials constituting the reactive thin film and Te.

Abstract: A phase-change recording medium having a recording layer (4) made of a Ge--Sb--Te alloy, comprises an interface reflection control layer (3) provided on a laser beam incident side of the recording layer (4). The interface reflection control layer (3) has an extinction coefficient k and a refractive index n, simultaneously satisfying: k.gtoreq.0.22n+0.14, k.ltoreq.0.88n-0.19, and n.ltoreq.2.8. From the foregoing, it follows that the intensity ratio between the reflected wave from and the incident wave on the interface between the recording layer (4) and the interface reflection control layer (3) is led to a specified range.As a result, for the recording layer (4) the ratio (Ac/Aa) of the light absorption rate (Ac) in the crystalline state to the light absorption rate (Aa) in the amorphous state increases. Furthermore, the optical contrast also has a sufficiently high value. It is therefore possible to produce a high quality readout signal in recording by overwriting.

Abstract: A phase change type optical recording medium comprises a dielectric layer 1a, a dielectric layer 1b, a phase change type recording layer and a second dielectric layer in the described order. The recording layer satisfies Ac/Aa.gtoreq.0.8 where Ac is an absorption coefficient of the recording layer in a crystalline region and Aa is an absorption coefficient of the recording layer in an amorphous region. The dielectric layer 1a comprises ZnS--SiO.sub.2 as main components and the dielectric layer 1b comprises a metal nitride or ZnS--SiO.sub.2 having an SiO.sub.2 content of 40 to 80 mol % as main components. At least an area of the second dielectric layer that is in contact with the recording layer comprises a metal nitride, a rare earth oxide, silicon oxide or ZnS--SiO.sub.2 having an SiO.sub.2 content of at least 40 mol% as main components. However, an optical recording medium comprising a dielectric layer 1a having an SiO.sub.

Abstract: The present invention is to provide a method for manufacturing the PCE optical information recording disk under control of not only the crystallization velocity but also the complex index of refraction and thus the reflectance on the disk surface.The PCE optical information recording disk is suitable to be used under the constant angular velocity (the constant rotational numbers wherein the disk has a characteristic that the crystallization velocity is designed to become faster from inside area of the disk to outside area in the radical direction thereof under control of not only the crystallization velocity but also the complex index of refraction and thus the reflectance on the disk surface.

Abstract: A method for manufacturing an optical information recording medium having an excellent mechanical strength, thermal stability, and improved overwrite cycle property can be provided by forming the dielectric layer by using a mixed target comprising ZnS and SiO.sub.2 in an atmosphere comprising rare gas and at least oxygen at the side where the dielectric layer does not contact to the recording layer. The optical information recording medium is manufactured by using the substrate, the recording layer comprising a material that varies reversibly between the optically identifiable states by an irradiation of a laser beam, and the dielectric layer at least one side of which has a two-layered structure at the upper and lower sides of the recording layer. At least one of the dielectric layers that does not contact to the recording layer is formed by using a mixed target comprising ZnS and SiO.sub.2 in a mixed atmosphere comprising rare gas and oxygen.

Abstract: An optical information recording medium includes a transparent substrate, a first dielectric layer, a recording layer, a second dielectric layer, a reflecting layer, and a third dielectric layer. The substrate constitutes an optical disk for performing a mark edge recording operation. The first dielectric layer is formed on the substrate. The recording layer is formed on the first dielectric layer and is irradiated with a laser beam to undergo a reversible phase change between a crystalline state and an amorphous state, thereby recording and erasing information. The recorded information is reproduced by detecting a change in optical characteristics accompanying a phase change of the recording layer. The second dielectric layer is formed on the recording layer. The first and second dielectric layers protect the recording layer. The reflecting layer is formed on the second dielectric layer and has a predetermined transmittance.

Abstract: A lead-free solder contains nickel, silver and tin. A soldered article is a workpiece containing a transition metal conductor capable of readily diffusing into melted tin; and the lead-free solder; wherein the lead-free solder is applied and bonded to the workpiece so as to be electrically and mechanically bonded to the transition metal conductor. The lead-free solder and soldered article barely cause electrode erosion during soldering or during aging after soldering, and have high tensile strength and thermal impact resistance.

Abstract: An aluminum or aluminum alloy surface which during use is exposed to sliding friction is coated to provide a chemical conversion coating of tin comprising 0.2-10.0 wt. % cobalt. For example, a swash plate type compressor has a cylinder block with cylinder bores disposed parallel to the axis of the cylinder block. A rotary shaft rotatably mounted within the cylinder block carries an aluminum swash plate. The swash plate has a coating preferably between 0.8 to 2.5 microns. The coating on the swash plate permits the use of low silicon alloy aluminum without the need of metal plating or high finish polishing.

Abstract: A method of introducing an anti-tarnish agent into the matrix of a tin coating to reduce oxidation and/or yellowing of the tin coating. The agent is preferably zinc, indium or phosphorous and can be deposited in a molten form to alloy with the existing tin coating. Alternatively, the existing tin coating may be exposed to a chemical bath including the agent and later heated to reflow the tin coating and agent thereby incorporating the agent into the matrix of the tin coating.

Abstract: An information recording medium which includes at least a recording layer, and first and second metallic layers disposed on an opposite side of an energy beam incident side of the recording layer and having different compositions, and in which the first one of the first and second metallic layers located closer to the recording layer contains Al, Ag, Au, Pt and Pd as its main components and a sum of contents of these atoms is 60% or more. Thereby recording and reproducing of information can be realized with a high reliability.

Abstract: An aluminum or aluminum alloy surface which during use is exposed to sliding friction has a chemical conversion coating of mostly tin with 0.2-10.0 wt. % cobalt and 0.1 to 12 wt. % bismuth. For example, a swashplate of a swashplate type compressor may be conversion coated on at least part thereof, that is the part that during use contact the shoes. Preferably, the coating is between 0.8 to 2.5 microns thick. The coating on the swash plate permits the use of low silicon alloy aluminum without the need of metal plating or high finish polishing.

Abstract: Disclosed is a phase change recording medium comprising a crystal section and an amorphous section, characterized in that the difference in reflectivity between the crystal section and the amorphous section is, for example, 15% or more when light with a wavelength of .lambda..sub.1 is applied and the difference in absorptivity between the crystal section and the amorphous section is, for example, 5% or less when light with a wavelength of .lambda..sub.2 is applied. Recording using light with a wavelength of .lambda..sub.2 brings about few opportunities of occurrence of cross-erasure because of a small difference in absorptivity between the crystal section and the amorphous section. Reproduction using light with a wavelength of .lambda..sub.1 after the recording using light with a wavelength of .lambda..sub.2 results in the production of satisfactorily regenerative signals because of a large difference in reflectivity between the crystal section and the amorphous section.

Abstract: An optical article made of a transparent polymer which includes terephthaloyl moieties, optionally, other aromatic diacid moieties; ethylene glycol moieties; isosorbide moieties; and, optionally, one or more other diol moieties, wherein the polymer has an inherent viscosity of at least about 0.35 dL/g as measured on a 1% solution (weight/volume) in o-chlorophenol at 25.degree. C.

Abstract: A rewritable optical information medium has a phase-change recording layer on the basis of an alloy of Ge--Sb--Te, which composition is situated within the pentagonal area PQRST in a triangular ternary composition diagram. These alloys show a complete erase time of 50 ns or less. CET-values below 45 ns are obtained with alloys situated on the tie-line connecting Te and the compound GeSb.sub.2 Te.sub.4 within the area PQRST. Such a medium is suitable for high speed recording (i.e. at least six times the CD-speed), such as for DVD-RAM and optical tape.

Abstract: An optical data recording medium utilizing reversible inter-crystalline-amorphous phase changes for recording, reproducing and erasing data as phase changes of a recording film caused by laser beam irradiation. The medium is formed by a lamination of a transparent substrate having tracking guide grooves for laser beam tracking, a base film formed on the substrate, a first protective film formed on the base film, a phase change type recording film formed on the first protective film, a second protective film formed on the recording film, and a reflecting film formed on the second protective film. Thus formed, the medium improves the over-writing characteristics of phase change type optical discs and permits high density recording.

Abstract: In an optical recording information recording medium of a structure having protection layers on both surfaces of a recording layer, overwrite cyclability is improved without deteriorating the reliability of recorded data.To achieve this, the first protection layer is deposited by a sputtering method from a target made of a mixture comprising ZnS and SiO.sub.2 without adding an O.sub.2 gas and a H.sub.2 gas to a sputtering atmosphere, the second protection layer is deposited by a sputtering method using a target made of a mixture comprising ZnS and SiO.sub.2 by adding an O.sub.2 gas and an H.sub.2 gas to the sputtering atmosphere.Especially, an optical information recording medium having a high reliability of recorded data and capable of overwriting of 300,000 cycles or more can be obtained, particularly, by controlling the partial pressure of the added O.sub.2 gas to 10.times.10.sup.-6 -50.times.10.sup.-6 Torr and the partial pressure of the added H.sub.2 gas to 20.times.10.sup.-6 -50.times.10.sup.

Abstract: A lead material for an electronic part having no adverse effect on the environment, having excellent solderability, desirable welding strength during welding and a low degree of nonuniform thickness of the plated layer during reflow processing. The lead material has a first plated layer and a second plated layer, both of which do not contain Pb, laminated on the surface of a conductive substrate in such order. The melting point of the second plated layer is lower than that of the first plated layer. The first and second plated layers are made of a Sn substance and a Sn alloy, respectively or vice versa.

Abstract: An phase change optical medium compatible with a flying head can include a substrate, a reflective layer, a first dielectric layer, a phase change information carrying layer, a second dielectric layer and a lubricant layer. The structure and materials used both protect the phase change layer from mechanical damage due to impact and from information-altering heat generated by impact.

Abstract: A composite coating provides a solderable surface on materials that cannot otherwise be soldered. The solderable coating is comprised of a composite layer of two components made of metals or metal alloys that function as a solderable material and as a material that enhances solder flow. A thin layer of at least one of the two components can also be incorporated along with the composite layer. A solderable coating can be deposited on a non-solderable surface by any of a variety of thermal spray techniques, including plasma spraying or wire arc spraying. These solderable coatings are particularly useful in the manufacturing of high power electronic components.

Abstract: The invention relates to a strip composite material with a base material of a metal or a metal alloy and a tin coating on the surface, whereby an intermetallic phase (IMP) is formed between the base material and the coating. In particular for achieving good wear and corrosion resistance of the composite material with a simultaneously oxide-free surface, 1 to 50 At.-%, preferably 6 to 30 At.-%, carbon (C) are embedded in an outer surface region of the tin coating up to a thickness D of approximately 2 .mu.m. A method (oil treatment) and apparatus for the manufacture of the composite material of the invention are also disclosed.

Abstract: A phase change type optical recording medium of Ge--Sb--Te system wherein number of overwritable operation has been increased is provided. The optical recording medium has a substrate and a recording layer of phase change type on the substrate, and the recording layer contains Ge, Sb and Te as its main elements, and at least one of Ag and Au in total content of 0.2 to less than 2.5 at % (excluding 2.5 at %).

Abstract: A phase-change optical recording medium has a substrate, and a lower heat-resistant protective layer, a recording layer capable of recording and erasing information by utilizing changes in the phase of a phase-change recording material in the recording layer, an upper heat-resistant protective layer and a light reflecting and heat dissipating layer, which are successively overlaid on the substrate in this order, the recording material including Ag, In, Sb and Te as the main elements, at least one additional element selected from the group (1) consisting of B, C, N, Al, Si and P, and at least one additional element selected from the group (2) consisting of halogen atoms and alkali metal elements.

Abstract: A method is provided for manufacturing a diamond-like carbon (DLC) coated optical phase-change recording medium for use with near-field optical head devices and which exhibits superior wear resistance and improved lifetime. According to the method, the surface of a composite optical phase-change media structure deposited onto a substrate is subjected to ion beam deposition of a DLC over-coat to a thickness of no greater than about 450 .ANG.. Preferably the DLC is ion beam deposited onto the phase-change recording layer at the surface of the medium structure or onto a germanium-containing adhesion-promoting interlayer to achieve the desired adhesion of the DLC to the surface of the medium structure.

Abstract: An electrical conductor has a copper base substrate coated with a tin base coating layer. To inhibit the formation of a copper/tin intermetallic and the resultant depletion of the free, unreacted, tin utilized as an oxidation and corrosion barrier, a barrier is interposed between the substrate and the coating. In a first embodiment, the barrier is formed from multiple constituent layers, at least one of which is copper. The thickness ("y") of the copper layer is dependent on the anticipated service temperature and satisfies the equation y=(-1.52+0.0871x+0.00859 t).+-.50% where t=anticipated time at the service temperature, x=anticipated service temperature (Celsius), and y=the thickness of the copper layer in microinches. In a second embodiment, the barrier layer is formed from one or more constituent layers, at least one of which is iron or iron base.

Abstract: An optical recording medium has a high hardness layer, first dielectric layer, recording layer, second dielectric layer and reflective layer. The hardness of the high hardness layer is larger than the hardness of the first dielectric layer, and the thickness of the second dielectric layer is in the range of 3 to 50 nm. Such a rewritable phase change type optical recording medium may show reduced degradation in the write-start portion and write-end portion of frequently rewritten sectors, and have good jitter characteristics.

Abstract: A high density optical disc having an optical disc protective structure for enabling a high density information recording and retrieval optical disc. The optical disc includes: a first protective film coated by a few tens of microns, on the reading surface of the optical disc, the first protective film having good transmissivity and high hardness against abrasion; and a second protective film coated by a few microns and having a lower surface energy and a minute molecular structure, providing protection against fingerprints on the surface of the first protective film.

Abstract: A method for preparing an optical recording medium of phase change type is provided. This recording medium comprises a substrate, a recording layer, and a lower and an upper dielectric layers provided in direct contact with the recording layer. In this method, a step of an exposure treatment wherein the surface of the lower dielectric layer is exposed to an oxidative atmosphere is conducted after forming the lower dielectric layer on the substrate and before forming the recording layer on the lower dielectric layer. A step of a heat treatment wherein said lower dielectric layer is heat treated may be carried out in addition to the exposure treatment.

Abstract: A rewritable optical information medium has a phase-change recording layer (3) on the basis of an alloy of Ge-Sb-Te-O, having the composition (Ge.sub.a Sb.sub.b Te.sub.c).sub.1-d O.sub.d, wherein:a+b+c=10.0001 a d a 0.035The addition of oxygen considerably speeds up the crystallization rate of Ge-Sb-Te materials. Such a medium is suitable for high speed recording (i.e. at least eight times the CD-speed), such as for DVD-RAM and optical tape. The amount of oxygen in the recording layer (3) can be used to tune the crystallization rate to the desired value.

Abstract: A connective medium is provided for use in ball grid assemblies for detachable connections between electronic devices and circuit boards. The medium includes novel, discrete spheres defining an inner metallic, spherical core and one or more outer, electrically conductive concentric, hard and non-deformable metallic layers of nickel, copper or alloys thereof and a coating of silver or gold thereon.

Abstract: A coating for protecting metal components against corrosion in a saline atmosphere comprises at least one layer of a tin/zinc alloy containing between 8% and 35% by weight of zinc deposited on a sublayer of an alloy of zinc/nickel containing between 10% and 16% by weight of nickel, the thickness proportion of the two alloys forming the coating being two-thirds in the case of the zinc/nickel alloy and one-third in the case of the tin/zinc alloy. The coating may also include an external chromate film.

Abstract: An optical disk can provide a sufficiently wide power margin for a recording power even when the optical disk has a high-recording density. The optical disk has a transparent substrate on which a recording layer in which information can be rewritten by at least irradiation of laser beam, a dielectric layer and a thermal conduction control layer are sequentially deposited. The thermal conduction control layer comprises a first low thermal conductivity layer, a first high thermal conductivity layer, a second low thermal conductivity layer and a second high thermal conductivity layer sequentially deposited thereon.

Abstract: An optical recording medium is provided which achieves a higher recording capacity. This optical recording medium includes a base formed of thermoplastic resin which has a thickness ranging from between approximately 0.3 to 1.2 nm, a guide groove formed on the base, at least a reflective film and a phase-change recording layer successively formed on the guide groove, arid a light transmissive layer having a thickness ranging from between approximately 3 to 177 .mu.m. In this optical recording medium, the unevenness .DELTA.t of the thickness of the light transmission layer is set within the range of:.DELTA.t.ltoreq..+-.5.26(.lambda./N.A..sup.4)(.mu.m)wherein N.A. represents a numerical aperture of an optical head device of the optical disk recording and/or reproducing apparatus and .lambda. represents the wavelength of laser light utilized by the optical disk recording and/or reproducing apparatus.

Abstract: A recordable element includes a substrate, an optical recording layer deposited on the substrate, a light reflecting layer deposited over the recording layer and an interfacial layer having a thickness in a range of 3 to 30 nm and interposed between the recording layer and the reflective layer, the optical recording layer containing Te.sub.a Ge.sub.b C.sub.c H.sub.d O.sub.e where a, b, c, d, and e are the atomic percents such that a+b+c+d+e=100, and wherein 10<a<40, 10<b<60, 5<c<35, 10<d<35, e.gtoreq.0; and the interfacial layer containing Ge.sub.w C.sub.x H.sub.y O.sub.z where w, x, y, and z are atomic percents such that w+x+y+z=100, and wherein 15<w<65, 5<x<35, 15<y<40, z.gtoreq.0. The recording element has its properties changed by heat treatment for a time and temperature selected so as to improve and stabilize its performance.

Abstract: An optical data storage medium transmissive to a laser beam and formed of a light transmissive substrate that provides mechanical support, and a light transmissive data substrate formed on the substrate. The data substrate is patterned to form block regions that block the laser beam from passing through, and pass regions that allow the laser beam to pass through, such that the blockage or passage of light through the optical storage medium reflects the type of data bits to be stored on the optical medium. In another embodiment a magneto-optical data storage medium which is also transmissive (or partly transmissive) to a laser beam includes a data magneto-optical data substrate formed on a substrate. The data substrate is recordable by patterning a magnetic domain with magnetic fields of opposite directions, such that each magnetic direction reflects the type of data bits to be stored on the optical medium.

Abstract: An improvement in production of an optical recording medium of phase change type is provided. In the present method, the step of repeated recording and erasing which had to be carried out after initialization and before shipment in the conventional process is eliminated. The optical recording medium produced by the present process retain good properties after repeated overwriting. In the process of the present invention, the prior art initialization step is replaced by modification treatment and the subsequent crystallization treatment. The modification treatment is a step wherein non-crystalline recording layer formed by sputtering is melted and cooled to change the crystal-lographic state into a non-crystalline state which is different from the non-crystalline state immediately after the formation of the recording layer. The crystallization treatment is a step conducted after the modification treatment wherein the recording layer in non-crystalline state is heated for crystallization.

Abstract: An optical recording medium has a phase-change recording layer embedded in a stack of thin layers arranged on a substrate. At least one of the dielectric layers adjacent to the recording layer comprises a carbide. The carbide layer is separated from the substrate and/or from a reflecting layer in the stack by a dielectric layer not containing a carbide. The thickness of the carbide layer either lies in a range from 2 to 8 nm or is substantially equal to the thickness of the adjacent dielectric layer.

Abstract: An electrical conductor consisting of an at least partially aluminium-based central core coated by continuous electrodeposition with at least one metal layer, including pretreatment of the surface of the core, characterized in that the following are subsequently performed successively on the core,a) an electrochemical deposition of copper in an aqueous bath maintained at a temperature of between 20.degree. C. and 60.degree.C., containing KCN, CuCN, K.sub.2 CO.sub.3 and KNaC.sub.4 H.sub.4 O.sub.6 with a current intensity of between 1 and 10 A/dm.sup.2 ;b) rinsing at ambient temperature;c) an electrochemical deposition of tin in an aqueous bath maintained at a temperature of between 20.degree. C. and 60.degree. C., containing essentially tin dissolved in methanesulphonic acid and, optionally, additives, with a current intensity of between 1 and 100 A/dm.sup.2 ;d) rinsing with water at 60.degree.C.

Abstract: An information memory apparatus includes an information storage medium having a thin film formed as a recording layer or a superresolution reading mask layer on a substrate directly or via a foundation layer to record and/or reproduce information stored in the form of an atom configuration change caused by irradiation of an energy beam. The information storage medium includes reflective layers as well. The information memory apparatus further includes a laser used for at least recording. The laser has a wavelength. The light absorptance of the recording layer or mask layer of the medium in a crystalline state at the wavelength is greater than or equal to the light absorptance of the recording layer or mask layer of the medium in an amorphous state at the wavelength.

Abstract: An optical recording medium includes a substrate, a first protection layer formed on the substrate, a recording layer formed on the first protection layer, a second protection layer formed on the recording layer, and a reflection heat radiating layer formed on the second protection layer. The recording layer is of a phase-change type in which the recording layer is changed from an amorphous state to a crystal state by a temperature raising and cooling process by projecting a laser beam onto the recording layer. The recording layer has an interface portion interfaced with one of the first and second protection layers. The interface portion has a thermal conductivity lower than that of a remaining portion of the recording layer.

Abstract: A writable compact disk has a plastic substrate, a recording layer, a reflecting layer, and a protective overcoat, the reflecting layer is comprised of a silver-palladium alloy, a silver-copper alloy, or a silver-palladium-copper alloy. By maintaining the palladium component of the alloy less that 15 at. % and the copper component of the alloy less than 30 at. %, the reflectance of the reflecting layer can be similar to the typical gold reflecting layer while jitter and NORP levels can be reduced for illumination power levels exceeding the power normally used to write on the recording layer.

Abstract: A metallic backing layer such as steel covered by a functional layer of AlSn, AlPb, CuPb, CuSn or CuZn, applied by spraying in air, and a softer covering layer applied to the functional layer by chemical or electrolytic deposition exhibits improved corrosion resistance, running-in behavior and conformability.

Abstract: A description is given of an reversible optical information medium comprising a substrate, a first dielectric layer, a phase-change recording layer on the basis of Ge--Sb--Te, a second dielectric layer, and a metal mirror layer. The recording layer comprises an alloy having the composition Ge.sub.50x Sb.sub.40-40x Te.sub.60-10x in atom %, wherein0.166.ltoreq.x.ltoreq.0.444and wherein the layer thickness d.sub.3 of said recording layer ranges between 25 and 35 nm. Such a medium is suitable for high speed recording (i.e. at least twice the CD-speed), and has a large cyclability of at least 10.sup.5 direct overwrite cycles.

Abstract: An optical information recording medium is provided in which the active layer is a phase change material capable of absorbing energy and being converted between a substantially amorphous state and a substantially crystalline state. The active layer contains nitrogen, which may be in the form of a nitride or nitrides of the constituent elements of the active layer, or may be a nitrided surface thereof. The inclusion of nitrogen inhibits localized shifting of the active material, which leads to degradation of the recording/erase properties of the medium. The optical recording medium includes a substrate, onto which is deposited in sequence a first dielectric layer, a nitrogen-containing active layer, a second dielectric layer, and a metallic reflecting layer. The second dielectric layer is made thin, so that the cooling rate of the active layer is increased to form a more uniform amorphous state.

Abstract: The present invention provides an optical recording medium using an amorphous-crystalline phase-change for recording and erasing, wherein reflectivity of an optical recording medium-constituting recording film in an amorphous state is larger than that of the optical recording medium-constituting recording film in a crystalline state, or wherein absorptivity of an optical recording medium-constituting recording film in an amorphous state is smaller than that of the optical recording medium-constituting recording film in a crystalline state.