Magnetic and transport properties of CeVO3
1995; Elsevier BV; Volume: 119; Issue: 1 Linguagem: Inglês
10.1016/0022-4596(95)80005-a
ISSN1095-726X
AutoresHoan C. Nguyen, John B. Goodenough,
Tópico(s)Electronic and Structural Properties of Oxides
ResumoMagnetic data are presented that indicate the VO3 array of the perovskite CeVO3 exhibits the same anomalous properties as in LaVO3, including (1) a first-order magnetostrictive distortion below a Tt < TN, (2) a canted-spin ferromagnetism below TN, (3) a reversal of the direction of the vanadium atomic moments on traversing Tt, and (4) suppression of Tt in an isostructural metastable phase prepared under hydrostatic pressure. The VCe exchange field operating at the Ce3+ : 4f1 configurations below TN does not change sign on traversing Tt. The Ce-atom magnetization reduces the field for nucleation of irreversible magnetization processes; both La0.5Ce0.5VO3 and CeVO3 exhibit MH hysteresis loops characteristic of hard ferromagnets, whereas the magnetization of LaVO3 remains reversible in fields H = ±50 kOe. For x ≥ 0.25, substitution of Sr for Ce in Ce1-xSrxVO3 does not create small-polaron V4+ ions, but delocalized V-3d states and an intermediate Ce4+/Ce3+ valence at the Ce atoms. Strong correlations among the itinerant V-π∗ electrons of stoichiometric, metallic SrVO3 reintroduce long-range magnetic order at low temperatures.
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