Electronic structure, ferroelectric properties, and phase stability of BiGaO3 under high pressure from first principles

Abstract

High-pressure behavior of BiGaO 3 has been investigated from 0 to 20 GPa using density functional theory. It is found that BiGaO 3 undergoes a pressure-induced first-order phase transition from pyroxene (Pcca) to monoclinic (Cm) at 3.5 GPa, and then to rhombohedral (R3c) at 5.2 GPa, and finally to orthorhombic (Pnma) structure at 7.4 GPa. The first phase transition (Pcca ? Cm) agrees well with the experimental results. At 5.2 GPa the possible coexistence of three ferroelectric phases, i.e., monoclinic Cm, tetragonal P4mm, and rhombohedral R3c has been predicted. The calculated values of spontaneous polarization for these phases are of 124.87, 123.48, 88.75 lC/cm 2 for Cm, P4mm, and R3c, respectively.

Complex Oxides under Simulated Electric Field: Determinants of Defect Polarization in ABO3 Perovskites

“…For metal elements of high electronegativity, we expect the corresponding ions should attract electrons more easily than those of metals with lower electronegativity. We can justify this hypothesis also by observing that the previously reported polarization of BiMO 3 (M = Al, Ga, Fe) [27][28][29] correlates positively with the electronegativity of the B-site cation. The po-larization of the lone-pair electrons on bismuth share some similarities with the polarization of the two trapped electrons in the oxygen vacancy treated in this work; they are both associated with local electronic states, the spatial distribution of which depends on the species of nearby ions.…”

Comparative density functional studies of BiMO3 polymorphs (M = Al, Ga, In) based on LDA, GGA, and meta-GGA functionals

“…The structural and electronic properties of these compounds were reported previously by other authors. 23,25,54,59,[70][71][72][73][74][75][76][77][78][79][80][81] Most of their results were obtained using the LDA or GGA. Here, we repeated them to compare with the results obtained using the AM05 and meta-GGA functionals, which have not been used to study the Firstly, we performed the optimization of the ambient pressure structures of BiAlO 3 , BiGaO 3 , and BiInO 3 , namely the perovskite rhombohedral R3c, pyroxene orthorhombic Pcca, and perovskite orthorhombic Pna2 1 , respectively.…”

Comparative Interrelationship of the Structural, Nonlinear-Optical and Other Acentric Properties for Oxide, Borate and Carbonate Crystals

“…Here, at the plotting of B-spline line, some points with a high level of values χ (2) > 53 pm/V for oxide crystals ZnTiO3, PbVO3, BiGaO3, BiFeO3,β-LiNbWO6 are not taken into account because of the absence of their data on the piezoelectric coefficient [68,[76][77][78][79][84][85][86]. In Figure 5, the maximal values of χ (2) are plotted for oxide crystals PbVO3 (53 pm/V, C4v) [68], β-LiWNbO6 (χ (2) ≈ 70 pm/V, C3v) [78][79][80][81][82][83][84][85][86][87][88][89], and our estimation of the values χ (2) for crystals ZnTiO3 (C3v) on the last Ps data [76] is also taken into account But, the higher χ (2) -level for the B-spline line very well corresponds to the χ (2) -level of these points. Now the most giant nonlinear optical coefficient d33 = 3401 pm/V is observed in the multiferroic BiFeO3 films due to the large ferroelectric polarization (Ps = 100 μC/cm 2 ) and coupling between magnetic and ferroelectric order parameters [88].…”