Reduction of the allotropic transition temperature in nanocrystalline zirconium: Predicted by modified equation of state (MEOS) method and molecular dynamics simulation

► Different developed formulae in MEOS method are presented. ► The phase stability curves are plotted and discussed for various phases. ► The allotropic transition temperature is decreased with reduced grain size. ► A molecular dynamics (MD) simulation is employed to confirm the MEOS results.