Ordering process and ferroelectricity in a spinel derived from FeV2O4

Article

关键词: JAHN-TELLER DISTORTIONS;    1ST-ORDER TRANSITION;    CATION DISTRIBUTION;    MAGNETIC-PROPERTIES;    MOSSBAUER SPECTRA;    IRON;    OXIDES;    DIFFRACTION;    MNV2O4;    IONS;   

DOI  :  10.1103/PhysRevB.85.054405

来源: SCIE

【 摘 要 】

The spinel FeV2O4 is known to exhibit peculiar physical properties, which is generally ascribed to the unusual presence of two cations showing a pronounced interplay between spin, orbital, and lattice degrees of freedom (Fe2+ and V3+ on the tetrahedral and octahedral sites, respectively). The present work reports on an experimental reinvestigation of this material based on a broad combination of techniques, including x-ray diffraction, energy dispersive, and Mossbauer spectroscopies, as well as magnetization, heat capacity, dielectric, and polarization measurements. Special attention was first paid to establish the exact cationic composition of the investigated samples, which was found to be Fe1.18V1.82O4. All the physical properties were found to point out a complex ordering process with a structural transition at T-S = 138 K, followed by two successive magnetostructural transitions at T-N1 = 111 K and T-N2 = 56 K. This latter transition marked the appearance of electric polarization, and magnetization data were analyzed in detail to discuss the nature of the magnetic state at T < T-N2. An overall interpretation of the sequence of transitions was proposed, taking into account two spin couplings, as well as the Jahn-Teller effects and the mechanism of spin-orbit stabilization. Finally, the origin of ferroelectricity in Fe1.18V1.82O4 is discussed on the basis of recent models.

【 授权许可】

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