Accession Number : AD0670520

Title :   PRESSURE DERIVATIVES OF THE ELASTIC CONSTANTS OF RUBIDIUM.

Descriptive Note : Technical rept.,

Corporate Author : CASE INST OF TECH CLEVELAND OHIO

Personal Author(s) : Pauer,Lyle A.

Report Date : MAY 1968

Pagination or Media Count : 38

Abstract : The pressure variation of the elastic stiffnesses of rubidium was measured at 195K by the ultrasonic pulse echo method. The values found are: dC44/dP = 1.48; dC'/dP = 0.229; dB sub s/dP = 3.63. The notation C' = (C11-C12)/2, B sub s = (C11+2C12)/3 was used. The results were compared with the predictions of the Fuchs theory of the electrostatic contribution to the shear stiffnesses of the alkali metals. The experimental observation that the elastic anisotropy C44/C' depends somewhat on pressure suggests the presence of another, minor, contribution to the shear stiffnesses, but the sense of the pressure dependence of C44/C' is not accounted for by including an ion core interaction or a Fermi contribution. The bulk modulus and its pressure derivative are well described by the simplest model of the binding energy. The ultrasonic Murnaghan equation of state fits well the compression data of Swenson. Values of the temperature coefficients, at constant volume, of the elastic stiffnesses are presented. (Author)

Descriptors :   (*RUBIDIUM, ELASTIC PROPERTIES), ANISOTROPY, PRESSURE, SHEAR STRESSES, METAL CRYSTALS, ULTRASONIC RADIATION, EQUATIONS OF STATE, THERMODYNAMICS, CHEMICAL BONDS

Subject Categories : Metallurgy and Metallography
      Mechanics
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE