The Transition from Nonmagnetic State to Ferromagnetic State of Co in a Pseudobinary Alloy CoTi_1−xAl_x

Abstract

The coexistence of ferromagnetic and nonmagnetic Co is found in a pseudobinary alloy CoTi_1−xAl_x by means of magnetization measurement and NMR of Co⁵⁹. The dependence of the component of the ferromagnetic Co on external field and on composition x result in a critical field H_c and a critical composition x_c where the magnetic state of Co in the alloy takes place transition from nonmagnetic state to ferromagnetic one or vice versa. The nonmagnetic state of Co at x=0.6 is identified with the strongly paramagnetic and exchange enhanced state with Stoner factor of 24.