Electron spectroscopy study of single-crystal CrTe

We study characterized single crystals of CrTe using photoemission spectroscopy (PES), x-ray absorption spectroscopy (XAS), and x-ray magnetic circular dichroism (XMCD) combined with density functional theory-based electronic structure calculations. X-ray diffraction confirms the hexagonal structure of CrTe (P63/mmc space group) and T-dependent magnetization M(T) shows a Curie temperature TC=340K, with a three-dimensional Ising-type critical behavior. A quantitative analysis of Cr3p and Te4d core levels using hard x-ray PES (HAXPES; hν=6.5keV) and low-energy PES (hν=100eV) indicates a nearly stoichiometric composition of Cr0.99±0.01Te. HAXPES of Te3p and 3d core levels show clean asymmetric single peaks with plasmon satellites. The Cr2p spectrum lies close to the Te3d spectrum but could be separated out and shows weak charge-transfer satellites. The Cr L-edge XAS-XMCD and Cr2p PES spectra could be simulated using charge transfer multiplet cluster-model calculations for a Cr2+ configuration with on-site Coulomb energy Udd=3.5eV and a negative charge-transfer energy Δ=-1eV. A sum-rule analysis of XAS-XMCD spectra indicates a very small orbital magnetic moment mo=0.01±0.01μB and a spin magnetic moment ms=2.49±0.2μB at T=25K, consistent with magnetization measurements and cluster-model calculations. Comparison of the calculated density of states (DOS) with the HAXPES valence band spectrum shows that the Te5p states dominates the spectrum due to the large photoionization cross section of Te 5p states with hard x rays. The Cr 3d partial DOS are spread between the Fermi level (EF) to ∼5-eV binding energy (BE), while the Te5p partial DOS are spread between the EF and ∼7-eV BE. The obtained electronic parameters suggest that CrTe is a p-type metal in the Zaanen-Sawatzky-Allen phase diagram, with p→p-type lowest-energy excitations.