Effects of Co for Mn substitution on the electronic properties of Mn2-xCoxVAl as probed by XPS

Abstract

Detailed theoretical and experimental investigations on the electronic and magnetic properties of the Heusler compounds Mn2-xCoxVAl with L21 structure are presented. The samples have been examined by X-ray diffraction, magnetization measurements and X-ray photoemission. The magnetic measurements show that the Curie temperatures decrease with Co content, ranging between 771 K (x = 0) and 289 K (x = 1), while the magnetization of the samples follows the Slater-Pauling rule.Additionally, electronic band structure calculations using the Korringa-Kohn-Rostoker (KKR) Greens function method have been performed. The evolution of the half-metallic character with the Co content x in the Mn2-xCoxVAl alloys is discussed based on the density of states (DOS) calculations. The influence of the Co doping on the individual magnetic moments of the Mn and V has been evidenced. Also, the small individual spin moments of Mn and V determined by theoretical calculations in MnCoVAl (x = 1) are confirmed by the Mn 3s and V 3s core level analysis of the X-ray photoemission spectroscopy investigations.