金属酸化物焼結体
(II) Ni-Co系焼結体の性質に及ぼす熱処理条件の影響
1962 年 31 巻 4 号 p. 276-285
詳細
1962 年 31 巻 4 号 p. 276-285
To obtain optimum sintering conditions for preparing uniform and stable thermistors of nickel and cobalt oxides, the effect of temperature on the crystal structure is examined on mixtures of powdered nickel and cobalt oxides by high temperature X-ray diffraction and differential thermoanalysis. From the physical properties observed on samples which were prepared by repeating a few times of pre-sintering at 1000°C for one hour then by being left to cool in furnace before the final sintering at 1350°C for one hour and also on those which were prepared by annealing at 700°C for one hour after sintered, the following conclusions are made: as the pre-sintering is repeated, the crystal grains become smaller, their distribution tends to become uniform and electrical resistivity becomes steadier; the annealing, if carried out properly, stabilizes the electrical characteristics.
