Coexistence of antiferromagnetic ordering and superconductivity in the Ba(Fe(0.961)Rh(0.039))(2)As(2) compound studied by Mossbauer spectroscopy
|Title||Coexistence of antiferromagnetic ordering and superconductivity in the Ba(Fe(0.961)Rh(0.039))(2)As(2) compound studied by Mossbauer spectroscopy|
|Publication Type||Journal Article|
|Year of Publication||2011|
|Authors||Wang P, Stadnik ZM, Zukrowski J, Thaler A, Bud'ko SL, Canfield PC|
|Journal Title||Physical Review B|
The results of a (57)Fe Mossbauer spectroscopy study between 2.0 and 294 K of superconducting Ba(Fe(0.961)Rh(0.039))(2)As(2) are reported. The main component of the electric field gradient tensor at 294 K is shown to be positive and its increase with decreasing temperature is well described by a T(3/2) power-law relation. The shape of the Mossbauer spectra below the Neel temperature T(N) = 55.5(1) K is shown to result from the presence of doping-induced disorder rather than of incommensurate spin-density-wave order. The measured hyperfine magnetic field reaches its maximum value at the critical temperature T(c) = 14 K and then decreases by 4.2% upon further cooling to 2.0 K. This constitutes direct evidence of the coexistence of and competition between superconductivity and magnetic order. The extrapolated value of the Fe magnetic moment at 0 K is determined to be 0.35(1) mu(B). The Debye temperature of Ba(Fe(0.961)Rh(0.039))(2)As(2) is found to be 357(3) K.