Magnetic Transition in CaFe_2As_2 Studied via Hyperfine Field Measurements for ~(66)Ga by TDPAD Technique.

摘要

Employing the time differential perturbed angular distribution (TDPAD) method we have measured hyperfine field of ~(66)Ga to study magnetic phase transition in CaFe_2As_2. The B_(hf) of ~(66)Ga comes out to be positive having a magnitude of 16 kG at 15 K. Complimenting the earlier hyperfine interaction studies, our data confirms the first order magnetic transition at T_N = 170 K. The critical exponent obtained from our data, however, indicates quasi-two dimensional magnetic order, possibly due to canting of Fe moments away from the basal plane.