Related papers: Different routes to charge disproportionation in p…
We report density functional theory (DFT) investigation of $B$-site doped CaFeO$_3$, a prototypical charge-ordered perovskite. At 290 K, CaFeO$_3$ undergoes a metal-insulator transition and a charge disproportionation reaction…
The incompatibility of partial d occupation on the perovskite B-site with the standard charge transfer mechanism for ferroelectricity has been a central paradigm in multiferroics research. Nevertheless, it was recently shown by density…
La doped SrFeO$_{3}$, La$_{1/3}$Sr$_{2/3}$FeO$_{3}$, exhibits a metal-to-insulator transition accompanied by both antiferromagnetic and charge ordering states along with the Fe-O bond disproportionation below a critical temperature near…
We have measured the temperature dependence of the photoemission and x-ray absorption spectra of La$_{1-x}$Sr$_x$FeO$_3$ (LSFO) epitaxial thin films with $x=0.67$, where charge disproportionation ($3{Fe}^{3.67+}\to 2{Fe}^{3+}+ {Fe}^{5+}$)…
Oxide superlattices represent a potent avenue for tailoring emergent electronic phases through sophisticated interfacial charge transfer and dynamic lattice distortions. This study systematically investigates the structural and electronic…
Since the discovery of charge disproportionation in the FeO$_2$ square-lattice compound Sr$_3$Fe$_2$O$_7$ by M\"ossbauer spectroscopy more than fifty years ago, the spatial ordering pattern of the disproportionated charges has remained…
The magnetic ordering of La$_{1/3}$Sr$_{2/3}$FeO$_3$ perovskite has been studied by neutron powder diffraction and $^{57}$Fe M\"ossbauer spectroscopy down to 2 K. From symmetry analysis, a chiral helical model and a collinear model are…
The archetypal $3d$ Mott insulator hematite, Fe$_2$O$_3$, is one of the basic oxide components playing an important role in mineralogy of Earth's lower mantle. Its high pressure-temperature behavior, such as the electronic properties,…
We have investigated the charge and spin ordering in Nd{1/3}Sr{2/3}FeO{3} with neutron diffraction technique. This sample undergoes a charge ordering transition accompanying charge disproportionation of 2Fe4+ -> Fe3+ + Fe5+. We measured the…
Polar antiferromagnetic metals have recently garnered increasing interests due to their combined traits of both ferromagnets and antiferromagnets for spintronic applications. However, the inherently incompatible nature of antiferromagnet,…
Charge-lattice fluctuations are observed in the layered perovskite manganite LaSr2Mn2O7 by Raman spectroscopy as high as 340 K and with decreasing temperature they become static and form a charge ordered (CO) phase below TCO=210 K. In the…
Some ABX3 perovskites exhibit different local environments (DLE) for the same B atoms in the lattice, an effect referred to as disproportionation, distinguishing such compounds from perovskites that have single local environments (SLE). The…
We have studied the interplay between orbital ordering, Jahn-Teller and GdFeO3-type lattice distortions in perovskite-type transition-metal oxides using model Hartree-Fock calculations. It has been found that the covalency between A-site…
CaCu$_3$Fe$_4$O$_{12}$ exhibits a temperature-induced transition from a ferrimagnetic-insulating phase, in which Fe appears charge disproportionated, as Fe$^{3+}$ and Fe$^{5+}$, to a paramagnetic-metallic phase at temperatures above 210 K,…
We studied structural, electronic and magnetic properties of a cubic perovskite BaFeO$_{3-\delta}$ ($0 \le \delta \le 0.5$) within the density functional theory using a generalized gradient approximation and a GGA+U method. According to our…
Magnetic and dielectric properties on a polycrystalline La0.7Bi0.3CrO3 have been investigated. A canted antiferromagnetic (CAF) phase transition giving weak ferromagnetism at TN = 230K has been observed. M-H at 10K shows non-saturating…
First-principles calculations were performed to investigate the ferroelectric properties of barium titanate and bismuth ferrite, as well as phonon dispersion of BaTiO3, using density functional theory and density functional perturbation…
Multiferroic materials have attracted great interests but are rare in nature. In many transitional metal oxides, charge ordering and magnetic ordering coexist, so that a method of engineering charge-ordered materials into ferroelectric…
We have explored spin, charge and orbitally ordered states in La1-xSrxMnO3 (0 < x < 1/2) using model Hartree-Fock calculations on d-p-type lattice models. At x=1/8, several charge and orbitally modulated states are found to be stable and…
Strong coupling among spontaneous structural symmetric breaking, magnetism and metallicity in an intrinsic polar magnetic metal can give rise to novel physical phenomena and holds great promise for applications in spintronics. Here, we…