The Room Temperature Elastic Behaviour of CsH2PO4

Abstract

The components of the elastic constant matrix of monoclinic caesium dihydrogen phosphate (CDP) have been determined using ultrasonic velocity measurements to be Cl1 = 28· 83 ± 0 '43, C22 = 26·67 ± O· 37, C33 = 65 ·45 ± 0'48, C44 = 8 .1O± 0,15, Css = 5 ·20± 0,24, C66 = 9·17 ± 0,22, C12 = 1l'4±3'6, C13 = 42·87±1·58, CIS = 5'13±0'67, C23 = 14·5±4·4, C 2S = 8'4±4'3, C3S = 7·50±0·81 and C46 = -2·25±0·31 GPa. Calculations of the velocity surfaces, ray directions, Young's modulus surfaces and linear compressibility show marked elastic anisotropy, which has been correlated with the chain and layer-like structure of CDP.