Thermistor materials and elements

Claim 1

A thermistor material in the form of a sintered body comprising (A) a matrix comprising at least one oxide selected from the group consisting of oxides of aluminum, of silicon, and of the elements magnesium, calcium, strontium and barium, and (B) a conductive path forming substance comprising at least one carbide selected from the group consisting of silicon carbide and boron carbide, wherein the volume ratio of silicon carbide to the matrix is up to about 1.24, and wherein the weight ratios of the matrix, silicon carbide and boron carbide are within the region defined by boundary lines joining corner coordinates (x, y, z) on a triangular plot, where x, y, z are the weight percent respectively of Al 2 O 3 , SiC and B 4 C, when the matrix is Al 2 O 3 and the corner coordinates are (95,0,5), (5,0,95), (50,50,0) and (95,5,0) or by the corner coordinates (Ayρm/ρa, Ay, Az) when the matrix is different from Al 2 O 3 , where ρm is the theoretical density of the matrix, ρa is the theoretical density of Al 2 O 3 , and A is a value such that A×ρm/ρa+Ay+Az=100, and the variables x, y, z have the preceding values specified for the corner coordinates when the matrix is Al 2 O 3 .