| 摘要 |
Process for producing crystalline layers of Cr cpds. of type AnB(1-n)Cr2X(4-R-s)YrZs where A and B are Cd, Co, Cu, Fe, Hg, Mn, Zn, Eu, Pb, Sr or Ba; X and Y are O, S Se or Te, Z is Cl, Br or I and 0 = n =1; 0= r =2; 0= s =2. The novelty is that on a single crystal substrate of either Cr2X3 or AnB(1-n) YkZ(1-k) where k = 0 or 1, a layer of the cpd. not forming the substrate is obtd. by vapour deposition, sputtering or chemical vapour deposition followed by heating for sufficient time to cause solid-state diffusion between the two. The heat-treatment is pref undertaken in a gas contg. Y in elementary or chemically bonded form, instead of Y, the gas may contain Z. The process is used in the mfr. of ferromagnetic semiconductors with a spinel or EuCr2S4 - structure and a negative magneto-resistance effect, for switching and memory devices. |
