简介 |
PROBLEM TO BE SOLVED : To obtain a porcelain composition having a relatively high relative permittivity and a high value of Q and capable of controlling the temperature coefficient of resonance frequency by including a rare earth element, Mg, Ta, Sb, Ti, Ca or Sr, having a specific composition and composing a main crystal of a perovskite type crystal phase. SOLUTION : A rare earth element is at least one kind of Y, La, Pr, Nd and Sm. The composition has a composition represented by the formula xMTiaO1+2a-yLn(Mg2/3Ta1/3)bO(3+3b)/2-zLm(Mg2/3Sb1/3)cO(3+3c)/2 [Lm and Ln are each a rare earth element; M is Ca or Sr; x, y and z are each mol%]. In Fig 1, a, b and c are each within the range of 0.950<=a<=1.050; 0.900<=b<=1.050 and 0.900<=c<=1.050. x, y and z are each located on lines or the interior of a polygon connecting point A (x=70, y=0, z=30), point B (x=50, y=0, z=50), point C (x=50, y=50, z=0) and point D (x=70, y=30, z=0). Good characteristics are obtained in a dielectric resonator, etc. |