Determination of Elastic Constants of K₂[PtCl₄] by Ultrasonic Measurements and Confirmation of Angular Dependence of Their Component by X-Ray Diffuse Scattering

Abstract

Elastic constants of K₂[PtCl₄] were determined at room temperature by using the ultrasonic pulse superposition method. The measured elastic stiffness constants are: C₁₁=31.0±0.6, C₃₃=23.2±0.6, C₄₄=6.04±0.37, C₆₆=4.68±0.35, C₁₂∼9.28 and C₁₃∼11.3 in units of 10¹⁰ dyn/cm². By the use of these constants profiles of the X-ray diffuse scattering due to long-wavelength phonons are well reproduced.