A recording layer for an optical data recording medium is described. Recording is performed by irradiating the recording layer with a laser beam. The recording layer contains a W oxide, an Fe oxide, and at least one of a Ta oxide and a Nb oxide. The recording layer contains 10-60 atomic % of Fe and a total of 3-50 atomic % of Ta and Nb relative to the total metal atoms therein.

Provided are a MnZnWO sputtering target having excellent crack resistance and a production method therefor. The MnZnWO sputtering target has a chemical composition containing Mn, Zn, W, and O. From an X-ray diffraction pattern of the MnZnWO sputtering target, a ratio P.sub.MnO/P.sub.W of a maximum peak intensity P.sub.MnO of a peak due to a manganese oxide composed only of Mn and O to a maximum peak intensity P.sub.W of a peak due to W is 0.027 or less.

Provided are a MnZnWO sputtering target having excellent crack resistance and a production method therefor. The MnZnWO sputtering target has a chemical composition containing Mn, Zn, W, and O. From an X-ray diffraction pattern of the MnZnWO sputtering target, a ratio P.sub.MnO/P.sub.W of a maximum peak intensity P.sub.MnO of a peak due to a manganese oxide composed only of Mn and O to a maximum peak intensity P.sub.W of a peak due to W is 0.027 or less.

Provided is a MnZnO sputtering target which can be used in DC sputtering, and a production method for the target. The MnZnO sputtering target comprises a chemical composition containing Mn, Zn, O, and at least one element X, the element X being a single one or two elements selected from the group consisting of W and Mo. The target has a relative density of 90% or more and a specific resistance of 110.sup.3 .Math.cm or less.

Provided is a MnZnO sputtering target which can be used in DC sputtering, and a production method for the target. The MnZnO sputtering target comprises a chemical composition containing Mn, Zn, O, and at least one element X, the element X being a single one or two elements selected from the group consisting of W and Mo. The target has a relative density of 90% or more and a specific resistance of 110.sup.3 .Math.cm or less.

Long term optical memory includes a storage medium composed from an array of silicon nanoridges positioned onto the fused silica glass. The array has first and second polarization contrast corresponding to different phase of silicon. The first polarization contrast results from amorphous phase of silicon and the second polarization contrast results from crystalline phase of silicon. The first and second polarization states are spatially distributed over plurality of localized data areas of the storage medium.

Long term optical memory includes a storage medium composed from an array of silicon nanoridges positioned onto the fused silica glass. The array has first and second polarization contrast corresponding to different phase of silicon. The first polarization contrast results from amorphous phase of silicon and the second polarization contrast results from crystalline phase of silicon. The first and second polarization states are spatially distributed over plurality of localized data areas of the storage medium.

Provided are media, systems and methods for optical data storage. A nanocomposite material for use as an optical data recording medium comprises nanoparticles embedded in a host matrix, wherein the host matrix comprises a material having a high structural stability, and the nanoparticles comprise optical functional components having a first physical or chemical state and a property of permanent transition to a second physical or chemical state upon exposure to corresponding optical radiation, whereby information may be recorded in the first and second physical or chemical states of the optical functional components over an extended time period.

Provided are media, systems and methods for optical data storage. A nanocomposite material for use as an optical data recording medium comprises nanoparticles embedded in a host matrix, wherein the host matrix comprises a material having a high structural stability, and the nanoparticles comprise optical functional components having a first physical or chemical state and a property of permanent transition to a second physical or chemical state upon exposure to corresponding optical radiation, whereby information may be recorded in the first and second physical or chemical states of the optical functional components over an extended time period.

The present invention relates to a method for recording data in a layer of a ceramic material and to a device for recording data in a layer of a ceramic material.