Surface acoustic wave and piezoelectric properties of (Pb, Ln) (Ti, Mn)O3 ceramics (Ln = rare earths)

Abstract

The surface acoustic wave (SAW) and piezoelectric properties of PbTi0₃ ceramics modified by the partial substitution of rare earths for Pb, particularly (Pb, Ln) (Ti, Mn)0₃ (Ln = La, Ce, Pr, Nd, Sm, or Gd) ceramics, are examined. The effects of the rare earths introduced on these properties are noted. Properties, such as velocities and electromechanical coupling factors, for bulk wave and SAW vary monotonically with the ionic sizes of the rare earths. On the other hand, the temperature coefficient of SAW delay time takes a minimum value when the Ln is Nd. It is shown that the variation of the temperature coefficient with rare earths corresponds well with those of the temperature coefficients of elastic constants C^E₃₃ and C^E₄₄.