Fe_3–xInSn_xO₆ (x = 0, 0.25, or 0.5): A Family of Corundum Derivatives with Sn-Induced Polarization and Above Room Temperature Antiferromagnetic Ordering

Abstract

Three new double corundum derivative compounds, Fe 3−x InSn x O 6 (x = 0. 0.25, or 0.5), were synthesized at high pressure and temperature (6 GPa and 1400− 1450 °C). All of the compounds order antiferromagnetically well above room temperature (T N = 608, 532, and 432 K for x = 0, 0.25, and 0.5, respectively). The x = 0 phase crystallizes as centrosymmetric R3̅ c, but the inclusion of closed-shell d 10 Sn 4+ induces x = 0.25 and 0.5 to crystallize as noncentrosymmetric R3c. Microprobe measurements indicate that for x = 0.25 and 0.5, the substitution of Sn 4+ is not offset by vacancies, which implies the presence of Fe 2+ , as corroborated by X-ray absorption near-edge spectroscopy and single-crystal X-ray structure refinements. Neutron powder diffraction experiments on x = 0.5 indicate that these compounds are canted A-type antiferromagnets that, like Fe 2 O 3 and InFeO 3 , consist of ferromagnetic layers that stack antiferromagnetically with a single magnetic transition. Weak ferromagnetic interactions persist to very high temperatures. Temperature-dependent second harmonic generation (SHG) measurements on x = 0.25 and 0.5 show a SHG response with ferroelectric-like hysteretic maxima that correspond with the respective magnetic transitions, which suggest coupling of the magnetic and polarization order. These new compounds provide more information about fine-tuning the electronic, magnetic, and structural properties of corundum-derived mutlferroics in the search for tunable high-temperature magnetoelectric materials.

Origin of Multiferroism in VOX2 (X = Cl, Br, I) Monolayers

“…Based on Density Functional Theory (DFT) [ 18 ], it has been demonstrated that the barrier height of the double-well potential in a monolayer of VOX 2 is similar to the height observed in typical ferroelectrics [ 24 , 25 ]. Consequently, the temperature of the FE phase transition is expected to be higher than room temperature [ 26 , 27 ]. This unequivocally indicates that the FE behaviour in the monolayer is a similar to materials that perform the “ rule”, despite V 4+ having a configuration and a spin .…”

Multiferroic kinks and spin-flop transition in Ni2InSbO6 from first principles

“…Its low temperature structure has a polar (non-centrosymmetric) rhombohedral R3 space group 9,10 similar to well known MF corundum derivative Ni 3 TeO 6 11,12 . A number of polar corundum derivatives have recently been synthesized and materials with above room temperature magnetism have been found 13,14 . These are promising candidates for magnetoelectric applications, in some of which polarization switching has been predicted 15 .…”