TEMPERATURE VARIATION OF THE GRUNEISEN CONSTANT IN CRYSTALS

Abstract

Barron's theory predicts an abrupt variation in the Griineisen constant of any crystal around a temperature of 0·2 BD. Such a variation is experimentally observed in copper, aluminium, vanadium, diamond and lithium fluoride. Fluorspar does not exhibit a conclusive evidence of such a variation though it appears quite probable. Iron pyrites does not exhibit any abrupt variation in y till 0'17 BD. The curve ofy vs. T/eD becomes flatter and flatter as the temperature is decreased. Zinc blende exhibits the drop at a much higher temperature than that predicted by Barron.