Surface Half-Metallicity and Electronic Structure Evolution in A-Type Antiferromagnet EuIn<sub>2</sub>P<sub>2</sub>.

Wu, Yunbo; Li, Tongrui; Chen, Xiaoli; Liu, Zhanfeng; Li, Yuliang; Shang, Zhengming; Zheng, Xin; Tian, Hui et al. · Nano Lett · 2025

basic_science · Level V

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Abstract

EuIn<sub>2</sub>P<sub>2</sub>, an A-type antiferromagnet, presents a compelling platform for exploring half-metallicity due to its layered structure and contrasting intra/interlayer magnetic ordering. Using angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT), we investigate the electronic structure evolution across its magnetic transition. Below <i>T</i><sub>N</sub>, ARPES reveals a Fermi level band splitting, indicative of a surface ferromagnetic exchange interaction. Notably, only one of the split bands crosses the Fermi level, suggesting potential surface half-metallicity. DFT calculations confirm this, showing no splitting in the bulk antiferromagnetic phase but reproducing the splitting in a ferromagnetic configuration. Above <i>T</i><sub>N</sub>, the band splitting collapses, accompanied by a Fermi surface volume change, reflecting the restoration of spin degeneracy. Surface potassium doping studies demonstrate tunable band dispersions and effective masses, highlighting the interplay between electron correlation and carrier concentration. Our results reveal surface ferromagnetism in EuIn<sub>2</sub>P<sub>2</sub> and highlight its promise for spintronic applications.