Evidence for a Correlated Insulator to Antiferromagnetic Metal Transition in CrN
Evidence for a Correlated Insulator to Antiferromagnetic Metal Transition in CrN
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DOI：
10.1103/physrevlett.104.236404
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发表时间：
2010-06-11
影响因子：
8.6
通讯作者：
Shin, S.
中科院分区：
文献类型：
--
作者：
Bhobe, P. A.;Chainani, A.;Shin, S.
研究了氮化铬（CrN）在T-N近似为286 K时的一级磁结构转变的电子结构。共振光电子能谱（PES）显示在费米能级的3D偏态密度和现场库仑能量U类似于4.5 eV的间隙，表明强的电子-电子相关。体积敏感的高分辨率（6毫电子伏）激光PES揭示了一个明确的费米边缘，表明反铁磁金属低于T-N。硬X射线Cr 2 p核能级PES显示了T-N上的T依赖性变化，这是由于相干态的屏蔽引起的，这一点通过使用实验观察到的U.电阻率证实高于T-N的绝缘体（E-g类似于70 meV）变成低于T-N的无序金属。因此，CrN从相关绝缘体转变为反铁磁金属，与磁结构转变相耦合。
We investigate the electronic structure of chromium nitride (CrN) across the first-order magneto-structural transition at T-N similar to 286 K. Resonant photoemission spectroscopy (PES) shows a gap in the 3d partial density of states at the Fermi level and an on-site Coulomb energy U similar to 4.5 eV, indicating strong electron-electron correlations. Bulk-sensitive high-resolution (6 meV) laser PES reveals a clear Fermi edge indicating an antiferromagnetic metal below T-N. Hard x-ray Cr 2p core-level PES shows T-dependent changes across T-N which originate from screening due to coherent states as substantiated by cluster model calculations using the experimentally observed U. Electrical resistivity confirms an insulator above T-N (E-g similar to 70 meV) becoming a disordered metal below T-N. Thus, CrN transforms from a correlated insulator to an antiferromagnetic metal, coupled to the magnetostructural transition.