| 摘要 |
PURPOSE:To provide a dielectric ceramic composition having a wide range of temperature coefficients for the resonance frequency temperature coefficient TCf ranging from a negative value to positive value by setting x, y, u, v, w, alphafor a composition expressed by a general expression (BaxSry)(ZnuMgvNbw)alphaO3. CONSTITUTION:BaCO3, SrCO3, ZnO, MgCO3, and Nb2O5 on the market are weighted for starting materials to obtain a predetermined composition after final sintering, and these are wet-mixed for 20 hours in a ball mill. Obtained material is dehydrated and dried, it is temporarily baked for about 2 hours at 1000 deg.C-1200 deg.C, this temporarily baked material is roughly crushed, and it is dry-crushed finely. Obtained powders are then granulated with a proper quantity of binder, moulded to be a cylindrical shape of a diameter of 12.7mm and a height of 7mm under a pressure, and baked for about 2 hours at 1400 deg.C-1600 deg.C to be dielectric ceramic material. For a composition expressed by a general expression of (BaxXry)(ZnuMgvNbw)alphaO3, x, y, u, v, w, alpha are set to be within ranges of equations I-VIII. A composition of a Qmax of more than 6000, a dielectric ratio of more than 36, and resonance frequency temperature coefficients(TCf) ranging from negative to positive can thus be obtained. |
