Abstract: A high-temperature superconducting thin film of compound oxide selected from the group consisting of:Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Ho.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Lu.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x,Sm.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Nd.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Gd.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x,Eu.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Er.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Dy,Ba.sub.2 Cu.sub.3 O.sub.7-x,Tm.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Yb.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x La.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x,(La, Sr).sub.2 CuO.sub.4-x,which is deposited on a substrate of sapphire, with the outer surface of the high-temperature superconducting thin film being covered with a protective crystalline film of SrTiO.sub.3.

Abstract: A process for manufacturing a superconducting elongated article such as a superconducting wire which is applicable for manufacturing a superconducting coil or the like. The process includes steps comprising filling a metal pipe with material powder of ceramic consisting of compound oxide having superconductivity, performing plastic deformation of the metal pipe filled with the ceramic metal powder to reduce the cross section of the metal pipe, and then subjecting the deformed metal pipe to heat-treatment to sinter the ceramic material powder filled in the metal pipe. The ceramic material powder may contain compound oxide having Perovskite-type crystal structure exhibiting superconductivity.The metal pipe may selected from a group comprising metals of Ag, Au, Pt, Pd, Rh, Ir, Ru, Os, Cu, Al, Fe, Ni, Cr, Ti, Mo, W and Ta and alloys including these metals as the base. The heat-treatment may be carried out at a temperature ranging from 700 to 1,000.degree. C.

Abstract: A high-temperature superconducting thin film of compound oxide selected from the group consisting of:Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Ho.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Lu.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x,Sm.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Nd.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Gd.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x,Eu.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Er.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Dy.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x,Tm.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, Yb.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, La.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x,(La, Sr).sub.2 CuO.sub.4-x,which is deposited on a substrate of MgO or SrTiO.sub.3, with the outer surface of the high-temperature superconducting thin film being covered with a protective crystalline film of SrTiO.sub.3.

Abstract: A process for preparing a superconducting thin film of K.sub.2 NiF.sub.4 -type oxides such as [La, Ba ].sub.2 CuO.sub.4, or [La, Sr ].sub.2 CuO having higher transition temperature of superconductivity which can be used for Josephson Junctions devices or the like by sputtering technique.The process of the present invention is characterized in that the target used in the sputtering technique is composed of a mixture of compounds which .contain at least La, one element M selected from a group of Ia, IIa and IIIa elements of the Periodic Table, and Cu. The compounds may be oxides, carbonates, nitrate or sulfates of La, said element M, and Cu. Said mixture which is used as the target is preferably sintered into a form of a sintered body. The substrate on which the thin film is deposited is preferably heated at a temperature between 100 and 1,200.degree. C. during sputtering and the deposited thin film is preferably heat-treated at a temperature between 600.degree. and 1,200.degree. C.

Abstract: A semiconductor heterojunction structure comprising a p-type diamond layer and an n-type cubic boron nitride layer on a surface of said p-type diamond layer. Such heterojunction structure is useful for a semiconductor device such as a diode, a transistor, a laser and a rectifier, particularly an element which emits light from blue light to ultraviolet light.

Abstract: An outer surface of a superconducting thin film of compound oxide such as YBa.sub.2 Cu.sub.3 O.sub.7-.delta. deposited on a substrate such as MgO and SrTiO.sub.3 is protected with a protective layer which is composed of amorphous inorganic material such as inorganic glass, amorphous oxide.

Abstract: An ohmic contact electrode formed on an n-type semiconductor cubic boron nitride by using a IVa metal or an alloy with a IVa metal or a layer of Au or Ag.

Abstract: A process for preparing a thin film of superconducting material is disclosed in which films are deposited from a defined target. The thin films prepared by the process are characterized by high critical temperature of superconductivity and a smaller discrepancy between the critical temperature and the onset temperature at which superconductivity is observed.

Abstract: A process for producing a superconducting material comprising a compound oxide represented by the general formula:(Ba, Ca).sub.x (.alpha., Dy).sub.1-x Tl.sub.y Cu.sub.1-y O.sub.3-zwherein ".alpha." represents Y or La; the atomic ratio of Ca to Ba is between 1% and 90%; the atomic ratio of Dy to .alpha. is between 1% and 90%; x, y and z are within the ranges of 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, and 0.ltoreq.z<1 respectively; and the expression of (Ba, Ca) and (.alpha., Dy) means that the respective elements occupy predetermined sites in a crystal in a predetermined proportion. The process comprises preparing a material powder, compacting the material powder and then subjecting the resulting compact to a final sintering operation and is characterized in that the material powder is(A) a powder mixture composed of powders selected from a group comprising (i) powders of elemental Ba, Cu, Ca, .alpha., Dy and Tl and (ii) powders of compounds each containing at least one of said elements Ba, Cu, Ca, .

Abstract: There can be provided a novel and useful process for the synthesis of hard boron nitride consisting essentially of single phase cubic boron nitride by a gaseous phase synthesis technique, which comprises adding a F atom-containing gas to the gaseous phase or adding a F atom-containing gas and H atom-containing gas to the gaseous phase, whereby the codeposited hexagonal boron nitride can selectively be etched and hard boron nitride of substantially single phase can finally be synthesized.

Abstract: A semiconductor device utilizing a non-doped diamond layer between a substrate and an active diamond layer. Such a structure decreases the resistivity and increases the carrier density. Further, when contacts are formed on the active layer, this layer structure reduces reverse leak current.

Abstract: An ohmic contact electrode is formed on an n-type semiconductor cubic boron nitride by using a IVB metal; an alloy with a IVB metal; a metal with Si or S; an alloy with Si or S; a metal with B, Al, Ga, or In; an alloy with B, Al, Ga, or In; a VB metal; or an alloy with a VB metal.

Abstract: This invention relates to new superconducting material having a composition represented by the general formula:A.sub.u B.sub.v C.sub.w D.sub.x E.sub.

Abstract: An ohmic contact electrode formed on an n-type semiconductor cubic boron nitride by using a IVa metal; an alloy with a IVa metal; a metal with Si or S; an alloy with Si or S; a metal with B, Al, Ga, or In; an alloy with B, Al, Ga, or In; a Va metal; or an alloy with a Va metal.

Abstract: A superconducting material and a process for producing a superconducting material comprising a compound oxide represented by the general formula:(Ba, .gamma.).sub.x (.alpha.,.beta.).sub.1 -.sub.x .epsilon..sub.y Cu.sub.1-y O.sub.3 -zin which".gamma." represents an element of the IIa group of the periodic table except Ba, an atomic ratio of .gamma. to Ba, being selected in a range between 1% and 90%,".alpha.represents Y or La,".beta." represents an element of the IIIa group of the periodic table but is different from .alpha., an atomic ratio of .beta. to .alpha. being selected in a range between 1 and 90%,".epsilon." represents a metal element of the IIIb group of the periodic table,x, y and z are numbers each satisfies ranges of O.ltoreq.x.ltoreq.1, O.ltoreq.y.ltoreq.1, and O.ltoreq.z.ltoreq.1 respectively, andthe expression of (Ba, .gamma.) and (.alpha., .beta.) mean that the respective elements occupy predetermined sites in a crystal in a predetermined proportion.

Abstract: An outer surface of a superconducting film of compound oxide such as YBa.sub.2 Cu.sub.3 O.sub.7-.delta. is protected with a protective layer which is composed of any one of (i) oxide of metal such as MgO, CaO, SrO etc, (ii) carbide such as SiC, or (iii) nitride such as BN.

Abstract: A heating process for producing a high quality diamond or c-BN film on a diamond or c-BN substrate comprising placing a diamond or c-BN substrate in vacuum, elevating the temperature and treating its surface with a chlorine containing gas, a fluorine containing gas, a nitrogen containing plasma or a hydrogen containing plasma. The treatment gas is then removed and feed gases are introduced which are suitable for growing a thin diamond or c-BN film on the surface substrate under chemical vapor deposition conditions.

Abstract: A now superconducting material comprising a compound oxide represented by the general formula:(Ba, Ca).sub.x (.alpha., Dy).sub.1-x Tl.sub.y Cu.sub.1-y O.sub.3-zwherein".alpha." represents Y or La;the atomic ratio of Ca to Ba is between 1% and 90%;the atomic ratio of Dy to .alpha. is between 1% and 90%;x, y and z are within the ranges of 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, and 0.ltoreq.z<1 respectively; andthe expression of (Ba, Ca) and (.alpha., Dy) mean that the respective elements occupy predetermined sites in a crystal in a predetermined proportion.

Abstract: In an ohmic contact electrode for the p-type semiconductor diamond, the electrode is formed of metals or metallic compounds containing boron on a p-type semiconductor diamond, so as to obtain a decreased contact resistance.

Abstract: A now superconducting material comprising a compound oxide represented by the general formula:(Sr,.gamma.).sub.x (La,.delta.).sub.1-x .epsilon..sub.y Cu.sub.1-y O.sub.3-zin which".gamma." represents an element of IIa group of the periodic table except Sr, an atomic ratio of .gamma. to Sr being selected in a range between 1% and 90%,".delta." represents an element of IIIa group of the periodic except La, an atomic ratio of .delta. to La is selected in a range between 1% and 90%,".epsilon." represents a metal element of Vb group of the periodic table, x, y and z are numbers each satisfies ranges of 0.ltoreq.x.ltoreq.1,0.ltoreq.y.ltoreq.1, and 0.ltoreq.z.ltoreq.1 respectively, and the expression of (Sr,.gamma.) and (La,.delta.) mean that the respective elements position predetermined sites in a crystal in a predetermined proportion.