Hai L. Feng

High-temperature ferrimagnetism driven by lattice distortion in double perovskite Ca2FeOsO6.

5d and 3d hybrid solid-state oxide Ca2FeOsO6 crystallizes into an ordered double-perovskite structure with a space group of P2₁/n with high-pressures and temperatures. Ca2FeOsO6 presents a long-range ferrimagnetic transition at a temperature of ~320 K (T(c)) and is not a band insulator, but is electrically insulating like the recently discovered Sr2CrOsO6 (T(c) ~725 K). The electronic stat of Ca2FeOsO6 is adjacent to a half-metallic state as well as that of Sr2CrOsO6. In addition, the high-T(c) ferrimagnetism was driven by lattice distortion, which was observed for the first time among double-perovskite oxides and represents complex interplays between spins and orbitals. Unlike conventional ferrite and garnet, the interplays likely play a pivotal role of the ferrimagnetism. A new class of 5d-3d hybrid ferrimagnetic insulators with high-T(c) is established to develop practically and scientifically useful spintronic materials.

High-Pressure Synthesis, Crystal Structures, and Magnetic Properties of 5d Double-Perovskite Oxides Ca2MgOsO6 and Sr2MgOsO6

Double-perovskite oxides Ca2MgOsO6 and Sr2MgOsO6 have been synthesized under high-pressure and high-temperature conditions (6 GPa and 1500 °C). Their crystal structures and magnetic properties were studied by a synchrotron X-ray diffraction experiment and by magnetic susceptibility, specific heat, isothermal magnetization, and electrical resistivity measurements. Ca2MgOsO6 and Sr2MgOsO6 crystallized in monoclinic (P21/n) and tetragonal (I4/m) double-perovskite structures, respectively; the degree of order of the Os and Mg arrangement was 96% or higher. Although Ca2MgOsO6 and Sr2MgOsO6 are isoelectric, a magnetic-glass transition was observed for Ca2MgOsO6 at 19 K, while Sr2MgOsO6 showed an antiferromagnetic transition at 110 K. The antiferromagnetic-transition temperature is the highest in the family. A first-principles density functional approach revealed that Ca2MgOsO6 and Sr2MgOsO6 are likely to be antiferromagnetic Mott insulators in which the band gaps open, with Coulomb correlations of ∼1.8-3.0 eV. These compounds offer a better opportunity for the clarification of the basis of 5d magnetic sublattices, with regard to the possible use of perovskite-related oxides in multifunctional devices. The double-perovskite oxides Ca2MgOsO6 and Sr2MgOsO6 are likely to be Mott insulators with a magnetic-glass (MG) transition at ∼19 K and an antiferromagnetic (AFM) transition at ∼110 K, respectively. This AFM transition temperature is the highest among double-perovskite oxides containing single magnetic sublattices. Thus, these compounds offer valuable opportunities for studying the magnetic nature of 5d perovskite-related oxides, with regard to their possible use in multifunctional devices.

Unusual magnetic hysteresis and the weakened transition behavior induced by Sn substitution in Mn3SbN

Substitution of Sb with Sn was achieved in ferrimagnetic antiperovskite Mn3SbN. The experimental results indicate that with an increase in Sn concentration, the magnetization continuously decreases and the crystal structure of Mn3Sb1-xSnxN changes from tetragonal to cubic phase at around x of 0.8. In the doping series, step-like anomaly in the isothermal magnetization was found and this behavior was highlighted at x = 0.4. The anomaly could be attributed to the magnetic frustration, resulting from competition between the multiple spin configurations in the antiperovskite lattice. Meantime, Hc of 18 kOe was observed at x = 0.3, which is probably the highest among those of manganese antiperovskite materials reported so far. With increasing Sn content, the abrupt change of resistivity and the sharp peak of heat capacity in Mn3SbN were gradually weakened. The crystal structure refinements indicate the weakened change at the magnetic transition is close related to the change of c/a ratio variation from tetrago...

Ba2NiOsO6 : A Dirac-Mott insulator with ferromagnetism near 100 K

The ferromagnetic semiconductor

High-pressure synthesis, crystal structure, and magnetic properties of KSbO3-type 5d oxides K0.84OsO3 and Bi2.93Os3O11

\mathrm{B}{\mathrm{a}}_{2}\mathrm{NiOs}{\mathrm{O}}_{6}

Crystal Structure and Magnetic Properties of Sr2LiOsO6

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High-pressure synthesis, crystal structure and magnetic properties of double perovskite oxide Ba2CuOsO6

{T}_{\mathrm{mag}}\ensuremath{\sim}100\phantom{\rule{0.16em}{0ex}}\mathrm{K}

High-Temperature Ferrimagnetism with Large Coercivity and Exchange Bias in the Partially Ordered 3d/5d Hexagonal Perovskite Ba2Fe1.12Os0.88O6

) was synthesized at 6 GPa and 1500 \ifmmode^\circ\else\textdegree\fi{}C. It crystallizes into a double perovskite structure [

Synthesis, crystal structures, and magnetic properties of double perovskites SrLaNiOsO6 and BaLaNiOsO6

Fm\ensuremath{-}3m

The role of nonmagnetic d0 vs. d10 B-type cations on the magnetic exchange interactions in osmium double perovskites

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