| 摘要 |
PURPOSE:To make small specific resistance and resistance change ratio by adding at least a kind, selected from the oxide of elements of niobium, tantalum and tungsten, to the main component consisting of the oxide of elements of manganese, cobalt and copper in terms of its element. CONSTITUTION:Manganese oxide, cobalt oxide, copper oxide, niobium pentoxide, tantalum pentoxide, and tungsten trioxide, all of which are in purity of 99.9% or higher, are wet-mixed for about 15 hours by a ball mill using urethane balls as pebbles. Then, after the above-mentioned mixture has been calcined at about 90 deg.C for two hours or thereabout, it is wet-pulverized again by the ball mill, and a molding operation is conducted. At this point, the compositional ratio of at least a kind selected from each oxide of niobium, tantalum and tungsten, which are added to the main component consisting of each oxide of manganese, cobalt and copper, should be 0.05 to 50mol%. As a result, a composition, having the excellent characteristics with time of the resistance change ratio of 5% at 125 deg.C with the specific resistance of 100OMEGA.cm or less, can be obtained. |
