High-Temperature Ferrimagnetic Half Metallicity with Wide Spin-up Energy Gap in NaCu₃Fe₂Os₂O₁₂

Abstract

A new oxide NaCu 3 Fe 2 Os 2 O 12 is synthesized using high pressure and temperature conditions. The Rietveld structural analysis shows that the compound possesses both A-and B-site ordered quadruple perovskite structure in Pn3̅ symmetry. The valence states of transition metals are confirmed to be Cu 2+ /Fe 3+ /Os 5.5+ . The three transition metals all take part in magnetic interactions and generate strong Cu 2+ (↑)Fe 3+ (↑)Os 5.5+ (↓) ferrimagnetic superexchange interactions with a high Curie temperature about 380 K. Electrical transport measurements suggest its half-metallic properties. The first-principles theoretical calculations demonstrate that the compound has a spin-down conducting band and a spin-up insulating band with a wide energy gap.

High-pressure synthesis and spin glass behavior of a Mn/Ir disordered quadruple perovskite CaCu3Mn2Ir2O12

“…The identical charge states between Mn and Ir therefore explains the B-site disorder in CCMIO. In particular, for most quadruple perovskite oxides with hybridized 3d-5d elements at the B site, the 3d-5d charge discrepancy is larger than two and then they form an ordered distribution, as exampled by CaCu3Fe2Re2O12, CaCu3Fe2Os2O12, and NaCu3Fe2Os2O12 [21,22,33].…”

Observation of A -site antiferromagnetic and B -site ferrimagnetic orderings in the quadruple perovskite oxide CaCu3Co2Liu1, Wang2, Ye3 et al. 2021Phys. Rev. BSelf Cite15010View full textAdd to dashboardCite

“…In comparison, there is a relatively large negative XMCD signal at the Re-L 2 edge and a very weak positive XMCD signal at the Re-L 3 edge, indicating an FiM spin-spin coupling between Co and Re ions. The very small XMCD signal for Re indicates that the Co 2+ (↑)Re 6+ (↓) FiM interaction is rather weak, consistent with the lower spin ordering temperature T C ∼ 20 K. The XMCD signal at the Cu-L 2,3 edges of CC-CRO is much weaker than that observed in CaCu 3 Cu 2+ (↑)Fe 3+ (↑)Re 5+ (↓) FiM coupling [1]. This feature rules out FM coupling between Cu 2+ ions, as a stronger XMCD signal would otherwise be expected.…”

“…A-site ordered quadruple perovskites, which have the chemical formula AA 3 B 4 O 12 , exhibit a wide variety of intriguing physical properties, such as high-temperature ferromagnetic (FM) or ferrimagnetic (FiM) ordering [1][2][3][4], charge disproportionation [5,6] colossal magnetoresistance [7], intermetallic charge transfer [5,6], half metallicity [1,3,4], negative thermal expansion [5,6], huge dielectric constant [8,9], multiferroicity, etc. [10,11].…”

“…Furthermore, if another TM ion B is used to partially substitute the B site in an ACu 2+ 3 B 4 O 12 compound, one may obtain both A-and B-site ordered quadruple perovskite ACu 2+ 3 B 2 B 2 O 12 . To date, long-range spin ordering in the reported A-and B-site ordered perovskites have always been observed to display a Cu 2+ (↑)B(↑)B (↓)-type FiM coupling [1][2][3][17][18][19]. Moreover, compared with the relative A 2 BB O 6 double perovskite, the quadruple one usually has a much higher spin ordering temperature.…”

Emergent physical properties of perovskite-type oxides prepared under high pressure

“…The isostructural NaCu 3 Fe 2 Os 2 O 12 compound was thus synthesized under high-pressure conditions. 66 The valence states of transition metals are determined to be Cu 2+ /Fe 3+ /Os 5.5+ . The decrease in the number of 5d-electrons of Os 5.5+ ions weakens the superexchange interactions of Cu-O-Os and Fe-O-Os, reducing T C to 380 K (Fig.…”