Dielectric, Elastic and Electromechanical Properties of K_1-x(NH₄)_xH₂PO₄ Solid Solutions in Paraelectric Phase

Abstract

Temperature dependences of dielectric permittivity ϵ₃₃, piezoelectric constant d₃₆ and elastic compliance S₆₆ of K_1-x(NH₄)_xH₂PO₄ ferro – antiferroelectric (FE - AFE) mixed crystals have been studied within temperature range 30 – 300 К. It was found a considerable contribution of the strain component x₆ to polarization P₃ near the FE transition temperature due to piezoelectric effect. Piezoelectric contribution to dielectric response in the vicinity AFE phase transition is weaker. It leads, in particular, to difference in the both shapes and positions of ϵ₃₃ and S₆₆ anomalies for K_0,25(NH₄)_0,75H₂PO₄ single crystal near the transition temperature.

Keywords:

• Solid solutions
• elastic compliance
• dielectric permittivity
• piezoelectric constant

Acknowledgments

Authors thank professor S.A. Gridnev for the fruitful discussion and doctor R.M. Fedosyuk for the crystals grown. Authors express great appreciations to professor V.S. Zakhvalinskii as well as to doctors E. Pilyuk and A. Khmara for their technical assistance in various parts of this work.

This work was supported by Russian Foundation for Basic Research (Grants N 11-02-90435-a and N 13-02-90473-a) and by State Foundation for Fundamental Studies of Ukraine (Grant N Φ53.2/070).