Abstract
The results of a Mössbauer spectroscopy study between 2.0 and 294 K of superconducting Ba(FeRh)As 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 power-law relation. The shape of the Mössbauer spectra below the Néel temperature 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 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) . The Debye temperature of Ba(FeRh)As is found to be 357(3) K.
3 More- Received 21 April 2011
DOI:https://doi.org/10.1103/PhysRevB.84.024509
©2011 American Physical Society