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Ultrasonic attenuation due to phonon-phonon interaction has been evaluated in Rubidium Fluoride (RbF) in a wide temperature range (100K to 600K) for longitudinal and shear waves along <100> & <110> directions and for shear waves polarised along different directions. Electrostatic and Born–Mayer potentials have been used to obtain SOEC & TOEC (i.e. the second order elastic constants and third order elastic constants), taking nearest–neighbour distance and hardness parameter as input data. SOEC & TOEC data obtained at different temperatures have been used to obtain Gruneisen parameters and non-linearity or anisotropy parameters which in turn have been used to evaluate the ultrasonic attenuation coefficients in Akhiezer regime for longitudinal and shear waves. Ultrasonic attenuation due to thermoelastic loss and Dislocation drag, due to screw and edge dislocations has also been evaluated. Results have been discussed and it has been found that at higher temperature p-p interaction is the principal cause of acoustical dissipation in metals. Contribution of thermoelastic loss is negligible as expected.
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