DE1515950

1,116,352. Semiconductor resistor. HITACHI SEISAKUSHO KABUSHIKI KAISHA. 27 July, 1965 [28 July, 1964], No. 31981/65. Heading H1K. A semi-conductor oxide comprises a crystalline structure of vanadium dioxide as a major component and having therein a solid solution of at least one element which raises or lowers the temperature at which the resistance changes abruptly. The element is preferably Cr, Ti, Ge, Fe, Co, Ni, Mn, Nb, W, Mo, or Ta. In a resistor having platinum electrodes, the VO 2 composition grains are surrounded by an oxide coating which electrically connects the grains. The oxide coating may be at least one oxide of the elements Ag, Mg, Ca, Ba, Sr, Pb, La, P, B, Te, V or Na or V 2 0 5 . Insulating oxides such as SiO 2 may also be incorporated in the oxide coating. The crystalline structure may be made by mixing the components, fusing in air to 1000‹ C., pulverizing, heating in NH 3 at 350- 400‹ C., milling, shaping into beads, rods, discs or flakes and sintering in a reducing or inert atmosphere to at least 100‹ C.