Electronic structure and phase transition in polar ScFeO3 from first principles calculations

Abstract

The properties of newly discovered polar ScFeO 3 with magnetic ordering are examined using Ab initio calculations and symmetry mode analysis. The GGA+U calculation confirms the stability of polar R3c Phase in ScFeO 3 and the pressure induced phase transition to non-polar Pnma phase.Octahedron tilting and structural properties as a function of applied pressure have been analyzed.The origin of polar phase is associated with instability of non-polar R3 � c phase and group theory using the symmetry mode analysis has been applied to understand this instability as well as the spontaneous polarization of polar R3c phase. The magnetic phase transition shows G-type AFM ordering of Fe 3+ ion within Goodenough-Kanamori theory and the possibility of magnetic spin structure has been analyzed by using energy analysis including spin canting possibility.

Comparative study of magnetic and electronic properties of room‐temperature polar magnets ScFeO3 and InFeO3

“…Experimental studies about the A FeO 3 ( A = Sc, In) compounds have been accompanied by first‐principles calculations based on density functional theory (DFT) . The latter works confirmed that both compounds present a relatively high spontaneous FE polarization ( P S ) along hexagonal c ‐axis, where the P S in ScFeO 3 (107 μC/cm 2 ) is larger than in InFeO 3 (96 μC/cm 2 ).…”

“…The latter works confirmed that both compounds present a relatively high spontaneous FE polarization ( P S ) along hexagonal c ‐axis, where the P S in ScFeO 3 (107 μC/cm 2 ) is larger than in InFeO 3 (96 μC/cm 2 ). The hard magnetic direction is found to be parallel to the c ‐axis, and an easy plane of magnetization within the hexagonal ab‐plane . The wFM component in the InFeO 3 was calculated to be 0.02 μ B /Fe‐atom directed along the y ‐axis within the ab‐plane.…”

“…For ScFeO 3 , the nearest‐neighbor exchange interaction constant was computed ( J nn = −3.3 meV), and a T N of 635 K was predicted using classical Monte Carlo simulation . The canting angle of the Fe spins was calculated to be ~0.48° . By the end, an unexpected behavior for type‐I MF was observed, that is, the electric polarization was found to be sensitive to the magnitude of the Fe spin magnetic moment …”

“…The Ref. investigated the same properties upon collinear and canted G‐type AFM state, but employing GGA + U with U = 4 eV. Conversely, the Ref.…”

“… studied magnetic properties of InFeO 3 upon canted G‐type AFM configuration treating the XC effects in terms of GGA ( U = 0) approach, but without discussing its electronic structure. In all three cited publications, the authors employed pseudopotential approach of DFT implemented into the VASP code …”