Structural, mechanical properties and stability of yttrium chalcogenides under high pressure

In this work, we have considered the pressure induced NaCl (B1) to CsCl (B2) phase transition of yttrium chalcogenides (YX; X = S, Se, Te). An extended interaction potential (EIP) model has been developed (including the zero point energy effect in three body interaction potential model). Phase transition pressures are associated with a sudden collapse in volume. Ultimately we provide bulk modulus and its pressure derivative, elastic constants and the structural phase stability of these compounds. The transition pressures at which these compounds undergo structural phase transition from NaCl to CsCl phase are calculated. It is found that the present model has promise to predict the phase transition pressure for yttrium chalcogenides