Structural and ferroelectric transitions in magnetic nickelate PbNiO3

X F Hao, A Stroppa, P Barone, A Filippetti, C Franchini, S Picozzi
2014 New Journal of Physics  
Density functional calculations have been tremendously useful in understanding the microscopic origin of multiferroicity and in quantifying relevant properties in many multiferroics and magnetoelectrics. Here, we focus on a relatively new and promising compound, PbNiO 3 . The structural, electronic and magnetic properties of its two polymorphs, i.e. the orthorhombic structure with space group Pnma and the rhombohedral LiNbO 3 -type structure with space group R3c have been studied by using
more » ... died by using density functional calculations within DFT+U and hybrid functional schemes. Our data convey an accurate description of the pressure-induced phase transition from the rhombohedral to orthorhombic phase at a predicted critical pressure of 5 GPa in agreement with the measured value of 3 GPa. Both phases show the G-type antiferromagnetic configuration as a magnetic ground state, but differ in the spatial anisotropy associated with nearest-neighbor exchange couplings, which is strongly weakened in the rhombohedral LiNbO 3 -type phase. The predicted large ferroelectric polarization of the rhombohedral phase (Hao et al 2012 Phys. Rev. B 014116) has been reexplored and analyzed in detail using partial density of states, Born effective
doi:10.1088/1367-2630/16/1/015030 fatcat:6gv3ygxvozfzvf6bjonfafj4ia