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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Vacancy-ordered antifluorite materials (A$_2$BX$_6$) are garnering renewedattention as novel magnetic states driven by spin-orbit coupling (SOC) can berealized in them. In this work, by pursuing density functional theorycalculations and model studies, we analyze the ground state electronic andmagnetic structure of face-centered cubic (fcc) antifluorites K$_2$ReCl$_6$(KReC, 5$d^3$), K$_2$OsCl$_6$ (KOsC, 5$d^4$), and K$_2$IrCl$_6$ (KIrC, 5$d^5$).We find that KReC stabilizes in the high-spin $S$ = 3/2 state instead of theexpected pseudo-spin $J_{eff}$ = 3/2 state. The former occurs due to largeexchange-splitting as compared to the SOC strength. On the contrary, the KOsCstabilizes in broken $J_{eff}$ = 0 ($S$ = 1) simple Mott insulating state whileKIrC stabilizes in $J_{eff}$ = 1/2 spin-orbit-assisted Mott insulating state.The presence of an isolated metal-chloride octahedron makes these antifluoritesweakly coupled magnetic systems with the nearest and next-nearest-neighborspin-exchange parameters ($J_1$ and $J_2$) are of the order of 1 meV. For KReCand KOsC, the $J_1$ and $J_2$ are estimated to be antiferromagnetic andferromagnetic, which leads to a Type-I antiferromagnetic ground state, whereasfor KIrC, both $J_1$ and $J_2$ are antiferromagnetic, hence, it stabilizes witha Type-III antiferromagnetic state. Interestingly, in their equilibriumstructure, these antifluorites possess large magnetic anisotropy energy (0.6-4meV/transition metal), which is at least one-to-two orders higher thantraditional MAE materials like transition metals and multilayers formed out ofthem. Moreover, with epitaxial tensile/compressive strain, the MAE enhances byone order, becoming giant for KOsC (20-40 meV/Os).

Breakdown of $J_{eff}$ = 0 and $J_{eff}$ = 3/2 states and existence of  large magnetic anisotropy energy in vacancy ordered 5$d$ antifluorites:  K$_2$ReCl$_6$, K$_2$OsCl$_6$, and K$_2$IrCl$_6$