铬单磷族化合物中磁性多样性的统一自旋-费米子框架
A Unified Spin-Fermion Framework for Magnetic Diversity in Chromium Monopnictides
- Department of Materials Science and Metallurgy, University of Cambridge（剑桥大学材料科学与工程系）
机构由 AI 辅助整理，请以论文原文为准。
中文总结 AI 辅助
本研究通过第一性原理计算等方法，揭示了铬单磷族化合物中化学压力驱动的交换重构机制，统一解释了从交变磁性到双螺旋反铁磁性及无磁有序的演变。
中文摘要 AI 辅助
等电子化合物通常预期表现出相关的电子、结构和磁性行为。然而，铬单磷族化合物CrX（X= Sb, As, P）却展现出从NiAs型CrSb中的高温交变磁性，经MnP型CrAs中的双螺旋反铁磁性，到MnP型CrP中缺乏可分辨的长程磁有序的显著演变。在此，我们结合非共线居里顺磁态下的第一性原理计算、结构分析、磁性相图计算和交换参数提取，为这一演变建立了统一的微观框架。这三种化合物均共享形式上高自旋的$d^5$构型，名义上为Cr$^{1+}$，并与主要具有磷族元素特征的巡游态耦合。从Sb到P，化学压力增强了配体的巡游性，并驱动结构从高对称的NiAs晶格向日益扭曲的MnP型网络演变。伴随的竞争性Cr-Cr交换重构有利于CrSb中的A型反铁磁性和CrAs中的双螺旋有序，同时使CrP处于具有紧密竞争的磁性倾向的阻挫状态附近。我们的结果表明，化学压力驱动的交换重构是一种通用机制，通过该机制，共同的自旋-费米子电子结构能够在强关联材料中产生对比鲜明的磁性相。
英文摘要
Isoelectronic compounds are generally expected to exhibit related electronic, structural, and magnetic behavior. Chromium monopnictides CrX (X= Sb, As, P), however, display a striking evolution from high-temperature altermagnetism in NiAs-type CrSb, through double-helical antiferromagnetism in MnP-type CrAs, to the absence of resolved long-range magnetic order in MnP-type CrP. Here, combining first-principles calculations in the non-collinear Curie-paramagnetic state, structural analysis, magnetic phase-diagram calculations, and exchange-parameter extraction, we establish a unified microscopic framework for this evolution. All three compounds share a formal high-spin $d^5$ configuration, nominally Cr$^{1+}$, coupled to itinerant states of predominantly pnictogen character. From Sb to P, chemical pressure enhances ligand itinerancy and drives the structural evolution from the high-symmetry NiAs lattice to increasingly distorted MnP-type networks. The accompanying reconstruction of competing Cr-Cr exchanges favors A-type antiferromagnetism in CrSb and double-helical order in CrAs, while placing CrP near a frustrated regime with closely competing magnetic tendencies. Our results establish chemical-pressure-driven exchange reconstruction as a general mechanism through which a common spin-fermion electronic structure can generate contrasting magnetic phases in strongly correlated materials.
