Abstract: A current/voltage non-linear resistor comprises a sintered body having a main component of ZnO, an electrode applied to a surface of the sintered body and an insulation material applied to another surface of the sintered body. The main component containing, as auxiliary components, Bi, Co, Mn, Sb, Ni and Al, and the contents of the auxiliary components are respectively expressed as Bi2O3, Co2O3, MnO, Sb2O3, NiO and Al3+, of Bi2O3: 0.3 to 2 mol %, Co2O3: 0.3 to 1.5 mol %, MnO: 0.4 to 6 mol %, Sb2O3: 0.8 to 7 mol %, NiO: 0.5 to 5 mol % and Al3+: 0.001 to 0.02 mol %; a Bi2O3 crystalline phase in the sintered body including an &agr;-Bi2O3 phase representing at least 80% of the total Bi2O3 phase.

Abstract: A current/voltage non-linear resistor comprises a sintered body having a main component of ZnO, an electrode applied to a surface of the sintered body and an insulation material applied to another surface of the sintered body. The main component containing, as auxiliary components, Bi, Co, Mn, Sb, Ni and Al, and the contents of the auxiliary components are respectively expressed as Bi2O3, Co2O3, MnO, Sb2O3, NiO and Al3+, of Bi2O3: 0.3 to 2 mol %, Co2O3: 0.3 to 1.5 mol %, MnO: 0.4 to 6 mol %, Sb2O3: 0.8 to 7 mol %, NiO: 0.5 to 5 mol % and Al3+: 0.001 to 0.02 mol %; a Bi2O3 crystalline phase in the sintered body including an &agr;-Bi2O3 phase representing at least 80% of the total Bi2O3 phase.

Abstract: A sintered body which can be formed into a resistor having a non-linear resistance includes zinc oxide is the principal composition and bismuth, cobalt, antimony, manganese and nickel respectively converted to expressed Bi2O3, Co2O3, Sb2O3, MnO and NiO as auxiliary compositions. The compositions contains 0.05 to 10 mol % of Bi2O3, 0.05 to 10 mol % of Co2O3, 0.05 to 10 mol % of Sb2O3, 0.05 to 10 mol % of MnO and 0.05 to 10 mol % of NiO; the content ratio of the Bi2O3 to the NiO is in a mole ratio of 0.5 or more but 1.5 or less, and the content ratio of the MnO to the Sb2O3 is in a mole ratio of 1.0 or less. Preferably, the composition contains at least one of 0.5 to 500 ppm of aluminum, converted to Al3+, and 10 to 1000 ppm of at least one or the other of boron and silver, converted respectively to B3+, and Ag+. The composition may also contain 0.01 to 1000 ppm of at least one of sodium, potassium, chlorine and calcium, converted respectively to Na+, K+, Cl− and Ca2+.

Abstract: A high resistivity layer is disclosed for a medal oxide voltage-nonlinear resistor (varistor) for arrestors and surge absorbers of the type having a sintered body containing zinc oxide as a major component and two spaced electrodes attached to the surface of the body wherein the electrodes are insulated from one another by the high resistivity layer. The high resistivity layer of the invention consists essentially of at least zinc ferrate (III). The high resistivity layer is formed by sintering a slurry containing ferric oxide (Fe.sub.2 O.sub.3) as a major component.

Abstract: A voltage-nonlinear resistor having a good polarity characteristics is manufactured by sintering a composition containing metal zinc, zinc oxide and at least one oxide selected from the group consisting of nickel oxide, zirconium oxide, yttrium oxide, hafnium oxide and scandium oxide, each component being contained in an amount within a specific range.