Relationship between the Bond Valence and the Temperature Coefficient of the Resonant Frequency in the Complex Perovskite (Pb _{1− <i>x</i>} Ca _<i>x</i> )[Fe _0.5 (Nb _{1− <i>y</i>} Ta _<i>y</i> ) _0.5 ]O ₃

Abstract

The temperature coefficient of the resonant frequency (TCF) of complex perovskite (Pb 1− x Ca x )[Fe 0.5 (Nb 1− y Ta y ) 0.5 ]O 3 ceramics ( x = 0.5, 0.55; 0.0 ≤ y ≤ 1.0) was investigated, relative to the bond valence of the A‐ and B‐site ions in the ABO 3 perovskite structure (such as the barium‐, strontium‐, and calcium‐based complex perovskites). The TCF of these complex perovskite compounds varied with the bond valence of the A‐ and B‐sites and the tolerance factor ( t ) in the perovskite structure. In the tilted region ( t &lt; 1.0), the tilting of the oxygen octahedra increased and the TCF decreased, because of the increased bond valence of the B‐site. Also, the dependence of TCF on the bond valence of the A‐site was similar to its dependence on t .