Temperature dependence of the hyperfine field at iron atoms around the nonmagnetic impurities Al and Ga

The temperature dependence of the hyperfine field at Fe atoms in iron‐based alloys containing Al and Ga impurities was measured by Mossbauer method between liquid nitrogen temperature and the Curie point. No difference was found in the values of the relative hyperfine fields at Fe atoms near and far from the impurity. This result is inconsistent with the prediction of a simple Heisenberg model, but is in good agreement with that of a band model.