Piezoelectric and Elastic Properties of Single Crystalline Se-Te Alloys

The piezoelectric constants, the electromechanical coupling factors and the elastic compliance constants of Se-Te alloys are studied by the transmission circuit method and/or the mechanical resonance method. The piezoelectric constants d₁₁ and d₁₄ decrease rapidly when the Te concentration increases within the range of 0∼25 at.% and then increase with the Te concentration up to 80 at.%. The values of d₁₁ and d₁₄ are 2.76·10^-6 and 1.95·10^-6 C.G.S. for pure Se and 3.1·10^-6 (±10%) and 1.9·10^-6 (±15%) C.G.S. for the alloy of 80 at.%, respectively. A similar tendency is observed in the electro mechanical coupling factors k₁₁ and k₁₄, which are 0.250 and 0.156 for pure Se and 0.25 (±10%) and 0.17 (±15%) for the alloy of 80 at.%, respectively. All elastic compliance constants do not change linearly with the Te concentration within the range of 0∼30 at.%, but at higher Te concentration they change almost linearly with the concentration.