Influence of Cr-atoms on the magnetic and electrical properties in Ho(Co1-xCrx)(2) compounds

AC magnetic susceptibility, electrical resistivity and X-ray Photoelectron Spectroscopy (XPS) measurements have been performed on the Ho(Co1-xCrx)(2) compounds with x=0.0, 0.03, 0.05, 0.10, 0.15 and 0.20. A strengthening of t he HoCo2 ferrimagnetism shows up through a rapid increase at small Cr conce ntration x of the Curie temperature TC which reaches a maximum around x = 0 .15. The lattice parameters also go through a maximum for the same concentr ation of Cr. A remarkable decrease of the density of states near the Fermi level is observed for the sample with x= 0.20. We correlate the changes of the Curie temperature with the decrease of d-electron concentration when Cr substitutes for Co.