PURPOSE: To enhance a nonlinear index to a greater degree by a method wherein pores are introduced in the sintered body manufactured from a zinc oxide- manganese compound.
CONSTITUTION: A manganese compound is added to and mixed in zinc oxide in such a manner that MnO becomes the ratio of 3 to 7mol% against ZnO+ MnO, and the mixture is sintered at 1100 to 1350°C at the final stage. In the sintering process, the porosity of the obtained sintered body is to be 15 to 50%. As a manganese compound, manganese oxide or a substance which can be converted into manganese oxide by firing may be used. The manganese compound in the state wherein it is dissolved by a solvent is mixed into zinc oxide. The obtained mixture is dried up, the solvent is removed by evaporation, the dried material is crushed and calcined. Then, a foaming agent is added to the calcined powder obtained as above, and they are pulverized and mixed uniformly. As a foaming agent, an organic substance, having the boiling point of 200°C, which is dissolved or evaporated at 600°C, and also having carbon, hydrogen, oxigen and/or nitrogen as constituting element, can be used. Then, in the firing process, the temperature of 1100 to 1350°C is adopted.
IGARI AKIHIDE
TOYODA MASAAKI
| JPS58225601A | 1983-12-27 |