Impurity Acousto‐Electric Effect

Abstract

AbstractThe acousto‐electric effect (AEE) and the electronic sound absorption in piezoelectric crystals containing traps are considered taking into account the electron‐sound wave interaction due to the change of the trap ionization energy with deformation. In the AEE additional odd and even components appear besides the conventional Weinreich voltage being proportional to the square of the piezoelectric modulus. The odd component depends on the deformation potentials, the even one (which does not change its sign when inverting the direction of the wave propagation) is proportional to the product of the piezoelectric modulus and the deformation potentials. The even voltage component may be of the same order of magnitude as the conventional odd one provided the traps are not too deep and are present in sufficient concentration. Results of the calculation are compared to experimental data on AEE in ZnS crystals. The combined interaction considered is shown to be the possible cause of the even AEE observed in these crystals.