Evidence for a correlated insulator to antiferromagnetic metal transition in CrN

Abstract

We investigate the electronic structure of Chromium Nitride (CrN) across the first-order magneto-structural transition at T_N ~ 286 K. Resonant photoemission spectroscopy shows a gap in the 3d partial density of states at the Fermi level and an On-site Coulomb energy U ~ 4.5 eV, indicating strong electron-electron correlations. Bulk-sensitive high resolution (6 meV) laser photoemission reveals a clear Fermi edge indicating an antiferromagnetic metal below T_N. Hard x-ray Cr 2p core-level spectra show 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. The electrical resistivity confirms an insulator above T_N (E_g ~ 70 meV) which becomes a disordered metal below T_N. The results indicate CrN transforms from a correlated insulator to an antiferromagnetic metal, coupled to the magneto-structural transition.

arXiv commentSubmitted to Physical Review Letters (February 2010) 11 pages, 3 figures in the main text, 1 Supplementary Information

References in corpus (6)

• Localized Superconductivity in the Quantum-Critical Region of the Disorder-Driven Superconductor-Insulator Transition in TiN Thin Films
• Nature of Well-Screened State in Hard X-ray Mn 2$p$ Core-Level Photoemission of La${}_{1-x}$Sr${}_x$MnO${}_3$ Films
• Magnetic stress as a driving force of structural distortions: the case of CrN
• Competition between Magnetic and Structural Transition in CrN
• Bulk screening in core level photoemission from Mott-Hubbard and Charge-Transfer systems
• Tunneling studies in a homogeneously disordered s-wave superconductor: NbN

Cited by in corpus (17)

• Effect of magnetic disorder and strong electron correlations on the thermodynamics of CrN
• Equation of state of paramagnetic CrN from ab initio molecular dynamics
• Vibrational free energy and phase stability of paramagnetic and antiferromagnetic CrN from ab-initio molecular dynamics
• Electronic structure of CrN: A comparison between different exchange correlation potentials
• The role of N defects in paramagnetic CrN at finite temperatures from first-principles
• Electronic structure of hole-doped delafossite oxides CuCr_{1-x}Mg_{x}O_{2}
• Structural and Magnetic Phase Transitions in Chromium Nitride Thin Films Grown by RF Nitrogen Plasma Molecular Beam Epitaxy
• Exchange Interactions in Paramagnetic Amorphous and Disordered Crystalline CrN-based Systems
• Electronic structure of an antiferromagnetic metal: CaCrO3
• Structural Twinning-induced Insulating Phase in CrN (111) Films
• Secondary Phase Limited Metal-Insulator Phase Transition in Chromium Nitride Thin Films
• Anisotropic electronic phase transition in CrN epitaxial thin films
• Strain Fields and the Electronic Structure of Antiferromagnetic CrN
• The Rise of Refractory Transition-Metal Nitride Films for Advanced Electronics and Plasmonics
• Momentum-resolved electronic structures and strong electronic correlations in graphene-like nitride superconductors
• Thermoelectric properties and electronic structure of Cr(Mo,V)Nx thin films studied by synchrotron and lab-based X-ray spectroscopy
• Synthesis of functional nitride membranes using sacrificial water-soluble BaO layers