Effect of Mn concentration on the spin glass transition temperature of Fe 0.70− xMn xAl 0.30 alloys

Abstract

Magnetization measurements on zero field cooled (ZFC) and field cooled (FC) samples as a function of temperature where made on Fe 0.70− x Mn x Al 0.30 alloys with 0≤ x≤0.10. Our data show the existence of two regimes of the spin glass temperature T f when increasing the concentration x of the Mn atoms. We found that T f decreases slowly with increasing x up to x=0.06 and then shows a rapid linear decrease above this concentration. The existence of two regimes of T f behavior with x may be attributed to the disappearance of ferromagnetic clusters which exist for low values of x ( x<0.06). Compared to the Mn-free alloy, the relative changes in T f are bigger and exceed 40% at x=0.10. The second regime ( x>0.06) is associated with more influence of x on T f.