Spin Wave Excitation in a Mechanically Alloyed Co2MnSi Solid Solution

Abstract

The spin wave excitation has been analyzed in a Co2MnSi solid solution compound. A Co2MnSi sample was prepared by utilizing a mechanical alloying technique in Ar atmosphere. After 72 hours of milling time, the Co2MnSi solid solution was transformed from a multiphase to a single broadening phase, which is essential in understanding the spin wave excitation in a nanocrystalline material. The magnetization was measured from 7 K to room temperature by using a superconducting quantum interference device (SQUID) magnetometer. The thermal-magnetization curve was found to obey the Bloch law, M S(T)=M S(0)(1−BT 3/2−CT 5/2). Based on this formula, the spin wave stiffness constant was calculated from the magnetization data at low temperatures. The values were 0.264 eV⋅A2 and 0.325 eV⋅A2 for 72 and 96 hours of milling time, respectively. The spectroscopic splitting g-factor was obtained via electron spin resonance (ESR) measurements at X-band (9.45 GHz).