Abstract: An electron-emitting material contains a first metal component selected from Ba, Sr and Ca and a second metal component selected from Ta, Zr, Nb, Ti and Hf and also contains oxynitride perovskite. The electron-emitting material has improved electron emission characteristics, restrained evaporation at elevated temperatures, and minimized consumption by ion sputtering. The electron-emitting material is prepared by firing a metal component-containing raw material disposed in proximity to carbon in a nitrogen gas-containing atmosphere to thereby create oxynitride perovskite.

Abstract: The PTC thermistor material of the invention comprises a matrix phase and electrically conductive phases substantially uniformly dispersed in the matrix phase, said conductive phases having a resistivity lower than that of the matrix phase, and has a resistivity changing sharply in the vicinity of the melting point of the conductive phases. The matrix phase is made up of any one of a polycrystalline ceramic material, a glass-polycrystalline ceramic composite material, a glass, a crystallized glass, and a polymer material, and the conductive phases are made up of a metal containing bismuth as a main component. It is thus possible to achieve a PTC thermistor material which can be controlled in terms of various properties such as the temperature at which PTCR property becomes available and the rate of resistivity change and so can be applied to circuit parts through which large currents pass in a normal operation state.

Abstract: A laminated chip varistor has a varistor element including at least one varistor layer and at least two inner electrodes which are laminated alternatively, and outer most layers comprising the same material as the varistor layer; and terminal electrodes electrically connected to the inner electrodes each formed at each of the both edge portions of the varistor element; wherein a surface roughness (R) of the varistor element is in the range of 0.60 to 0.90 .mu.m.

Abstract: The invention provides a voltage-dependent nonlinear resistor porcelain in the form of a ZnO system sintered body comprising zinc oxide as a major component and at least one of rare earth element oxides, cobalt oxide, chromium oxide, at least one of Group IIIb element oxides, at least one of Group Ia element oxides, 0.01 to 2 atom % calculated as Ca of calcium oxide, and 0.001 to 0.5 atom % calculated as Si of silicon oxide as subordinate components, the atomic ratio of calcium to silicon (Ca/Si) ranging from 0.2 to 20. With the atomic ratio of calcium to silicon (Ca/Si) set between 0.2 and 20, preferably between 2 and 6, the element has a significantly increased load life at high temperature and humidity. The element experiences less deterioration of the asymmetry of its volt-ampere characteristic between different directions of DC conduction. If magnesium oxide is added to the composition in an amount of 0.

Abstract: A voltage-dependent nonlinear resistor or varistor ceramic composition consists essentially of (1) an oxide of the formula: {Sr.sub.(1-x-y) Ba.sub.x Ca.sub.y }.sub.z TiO.sub.3 wherein 0.3<x.ltoreq.0.9, 0.1.ltoreq.y.ltoreq.0.5, x+y.ltoreq.1, and 0.84<z<1.16, (2) 0.001 to 5.000 mol % of at least one oxide of niobium, tantalum, tungsten, manganese or R wherein R is yttrium or lanthanide, (3) 0.001 to 5.000 mol % of SiO.sub.2, and (4) 0.001 to 5.000 mol % of MgO. When the varistor voltage is controlled by changing a re-oxidizing temperature without changing the composition, a satisfactory nonlinear index .alpha. is available over a wide range of varistor voltage. The dependency of varistor voltage on heat treating temperature is reduced.