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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Electronic structure of Fe and magnetism in the 3d/5d double perovskites Ca2FeReO6 and Ba2FeReO6

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Granado, E. [1] ; Cezar, J. C. [2] ; Azimonte, C. [1] ; Gopalakrishnan, J. [3] ; Ramesha, K. [3]
Total Authors: 5
[1] Univ Campinas UNICAMP, Gleb Wataghin Inst Phys, BR-13083859 Campinas, SP - Brazil
[2] Lab Nacl Luz Sincrotron, Caixa Postal 6192, BR-13083970 Campinas, SP - Brazil
[3] Indian Inst Sci, Solid State & Struct Chem Unit, Bangalore 560012, Karnataka - India
Total Affiliations: 3
Document type: Journal article
Source: Physical Review B; v. 99, n. 19 MAY 9 2019.
Web of Science Citations: 0

The Fe electronic structure and magnetism in (i) monoclinic Ca2FeReO6 with a metal-insulator transition at T-MI similar to 140 K and (ii) quasicubic half-metallic Ba2FeReO6 ceramic double perovskites are probed by soft x-ray absorption spectroscopy (XAS) and magnetic circular dichroism (XMCD). These materials show distinct Fe L-2,L-3 XAS and XMCD spectra, which are primarily associated with their different average Fe oxidation states (close to Fe3+ for Ca2FeReO6 and intermediate between Fe2+ and Fe3+ for Ba2FeReO6) despite being related by an isoelectronic (Ca2+/Ba2+) substitution. For Ca2FeReO6, the powder-averaged Fe spin moment along the field direction (B = 5 T), as probed by the XMCD experiment, is strongly reduced in comparison with the spontaneous Fe moment previously obtained by neutron diffraction, consistent with a scenario where the magnetic moments are constrained to remain within an easy plane. For B = 1 T, the unsaturated XMCD signal is reduced below T-MI consistent with a magnetic transition to an easy-axis state that further reduces the powder-averaged magnetization in the field direction. For Ba2FeReO6, the field-aligned Fe spins are larger than for Ca2FeReO6 (B = 5 T) and the temperature dependence of the Fe magnetic moment is consistent with the magnetic ordering transition at T-C(Ba) = 305 K. Our results illustrate the dramatic influence of the specific spin-orbital configuration of Re 5d electrons on the Fe 3d local magnetism of these Fe/Re double perovskites. (AU)

FAPESP's process: 17/10581-1 - Emergent phenomena in reduced dimension systems
Grantee:Pascoal Jose Giglio Pagliuso
Support type: Research Projects - Thematic Grants
FAPESP's process: 18/20142-8 - Vibrational dynamics, spin waves and orbital excitations in transition-metal oxides
Grantee:Eduardo Granado Monteiro da Silva
Support type: Regular Research Grants