Electron spin–spin relaxation in dilute magnetic semiconductor Zn1−xMn2+xAs2

Abstract We have investigated magnetic phase transitions for the dilute semiconductors Zn 1− x Mn 2+ x As 2 ( x =0, 0.23, 0.33), by estimating the spin–spin relaxation times T 2 in the temperature range 113–360 K. From ZnMn 2 As 2 , a critical anomaly in T 2 was found around T AF =175 K, consistent with anomalous behavior in magnetization observed previously. In Zn 1− x Mn 2+ x As 2 with x =0, 0.23 and 0.33, such an anomaly in T 2 was found at 225 and 235 K, respectively.