Pressure effect on the properties of magnetic moments and phase transitions in YMnO3 from first principles

Abstract

We report the properties of magnetic, electronic, phonon frequencies and magnetic phase transitions in orthorhombic perovskite YMnO₃ by means of first-principles calculations. Our results argue that the magnetic ground state is indeed E-type antiferromagnetic ordering at zero temperature and zero pressure. In the range of 0 to 150 GPa, the magnetic phase undergoes two evolutions: first is E(Pmn2₁)-to-A(Pnma)-AFM phase at around 48 GPa, corresponding to the ferroelectric to paraelectric phase transition; second is A-to-G-AFM phase at around 131.7 GPa. The Mn³⁺ magnetic moments of the considered magnetic configurations exhibit a mutation (i.e., they decrease nearly by 50%) between 40 and 50 GPa. In parallel, to further investigate the magnetic ground states at different pressures, we also analyze the phonon spectra and electronic properties.