Structure, sound velocity, and thermal conductivity of the perovskite NdGaO3

X-ray (300 K) and ultrasonic (77–270 K) studies and measurements of the thermal conductivity (30–300 K) are carried out on single-crystal samples of NdGaO3 in different crystallographic directions. The values of the lattice parameters of NdGaO3 are refined. The sound velocities in the principal crystallographic directions are measured, and the elastic constants and Debye temperature are calculated. The observed anisotropy of the thermal conductivity is described in the framework of a gaskinetic model and is linked to the anisotropy of the interaction parameters of the acoustical and optical phonons.