Magnetic behavior of isolated Mo impurities in antiferromagnetic Cr metal

We report experimental and theoretical studies on the magnetic moment and hyperfine field of isolated Mo impurities in an antiferromagnetic Cr host. The magnetic response of 92,94Mo, measured by means of the time differential perturbed angular distribution (TDPAD) technique, show the saturation hyperfine field Bhf(0) to be −4.7T. In addition, we find evidence of short range antiferromagnetic spin correlation above TN, revealed from the observation of large Bhf values at temperatures far above TN. Our ab initio calculations, based on the generalized gradient approximation (GGA) of density functional theory (DFT), yield an induced magnetic moment of 0.45μB for the Mo impurity in Cr. The magnitude of the calculated hyperfine field Bhfcal=−3.35T closely agrees with the experimental value. The results presented in this work would be helpful for a common understanding of hyperfine fields of impurity atoms in ferro- and antiferromagnetic materials.