English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The Fe electronic structure and magnetism in (i) monoclinic Ca$_2$FeReO$_6$with a metal-insulator transition at $T_{MI} \sim 140$ K and (ii) quasi-cubichalf-metallic Ba$_2$FeReO$_6$ ceramic double perovskites are probed by softx-ray absorption spectroscopy (XAS) and magnetic circular dichroism (XMCD).These materials show distinct Fe $L_{2,3}$ XAS and XMCD spectra, which areprimarily associated with their different average Fe oxidation states (close toFe$^{3+}$ for Ca$_2$FeReO$_6$ and intermediate between Fe$^{2+}$ and Fe$^{3+}$for Ba$_2$FeReO$_6$) despite being related by an isoelectronic(Ca$^{2+}$/Ba$^{2+}$) substitution. For Ca$_2$FeReO$_6$, the powder-averaged Fespin moment along the field direction ($B = 5$ T), as probed by the XMCDexperiment, is strongly reduced in comparison with the spontaneous Fe momentpreviously obtained by neutron diffraction, consistent with a scenario wherethe 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 amagnetic transition to an easy-axis state that further reduces thepowder-averaged magnetization in the field direction. For Ba$_2$FeReO$_6$, thefield-aligned Fe spins are larger than for Ca$_2$FeReO$_6$ ($B=5$ T) and thetemperature dependence of the Fe magnetic moment is consistent with themagnetic ordering transition at $T_C^{Ba} = 305$ K. Our results illustrate thedramatic influence of the specific spin-orbital configuration of Re $5d$electrons on the Fe $3d$ local magnetism of these Fe/Re double perovskites.

Electronic structure of Fe and magnetism in the $3d/5d$ double perovskites Ca$_2$FeReO$_6$ and Ba$_2$FeReO$_6$