Thermodynamical Behaviour of PdSe₂ while Subjected Isothermally to High Pressure - Axial Level Analysis

Abstract:

We study thermodynamically the behaviour of PdSe2 while subjected to high pressure under isothermal conditions. The present paper continues the study started in [1]. Here we present the results of the axial calculations and analyses. Specific lengths, linear adjusted Gibbs free energy changes and linear adjusted entropy generations were studied along each spatial axis separately. We found that the first-order transition from PdS2 structure type to pyrite one at 20oC is accompanied by saltatory contraction of a and b specific lengths and respective saltatory expansion of c specific length. Under 300oC all specific lengths contract saltatory. In the transition point under 20oC PdSe2 gains saltatory stability along a and b axis and looses along c one, respectively. Besides, the loose along c axis is bigger than the gains along a and b ones. Under 300oC the transition is accompanied by slight gain of stability along all three spatial axes. Plateaux duration affects the stability of PdSe2 strongly under higher temperature.