Cu-site disorder in CuAl2O4 as studied by XPS spectroscopy
I. S. Zhidkov+*, A. A. Belik×, A. I. Kukharenko+, S. O. Cholakh+, L. S. Taran*, A. Fujimori°, S. V. Streltsov*+, E. Z. Kurmaev*+
+Institute of Physics and Technology, Ural Federal University, 620002 Yekaterinburg, Russia
*M. N. Mikheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620108 Yekaterinburg, Russia
×International Center for Materials Nanoarchitectonics (WPI-MANA),
National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, 305-0044, Ibaraki, Japan
°Department of Applied Physics, Waseda University, Shinjuku-ku, 169-8555 Tokyo, Japan
Abstract
The results of full study of X-ray photoelectron spectra (XPS)
of spin-liquid candidate CuAl2O4 including the measurements of high-energy
resolved core level (Cu 2p, Al 3p, O 1s), Cu LMM Auger and valence
band (VB) spectra are presented. The comparison of obtained results with
spectra of reference samples and specially performed density functional
theory calculations has confirmed a finite Cu site-disorder in
CuAl2O4, where about 30 % of Cu2+ ions occupy the octahedral
sites. Obtained valence band spectra can be used in further theoretical
studies aimed on the investigation of electronic and magnetic properties
of this mysterious material.