We report the structural, magnetic and electronic transport properties of SrFe2−xCuxAs2 single crystals grown by self-flux technique. SrCu2As2 and SrFe2As2 both crystallize in ThCr2Si2-type (122-type) structure at room temperature, but exhibit distinct magnetic and electronic transport properties. The x-ray photoelectron spectroscopy(XPS) Cu-2p core line position, resistivity, susceptibility and positive Hall coefficient indicate that SrCu2As2 is an sp-band metal with Cu in the 3d10 electronic configuration corresponding to the valence state Cu1+. The almost unchanged Cu-2p core line position in SrFe2−xCuxAs2 compared with SrCu2As2 indicates that partial Cu substitutions for Fe in SrFe2As2 may result in hole doping rather than the expected electron doping. No superconductivity is induced by Cu substitution on Fe sites, even though the structural/spin density wave(SDW) transition is gradually suppressed with increasing Cu doping.
@article{arxiv.1212.0295,
title = {Physical properties in hole-doped SrFe$_{2-x}$Cu$_x$As$_2$ single crystals},
author = {Y. J. Yan and P. Cheng and J. J. Ying and X. G. Luo and F. Chen and H. Y. Zou and A. F. Wang and G. J. Ye and Z. J. Xiang and J. Q. Ma and X. H. Chen},
journal= {arXiv preprint arXiv:1212.0295},
year = {2012}
}