Anisotropic hyperfine field fluctuation in La/sub 0.67/Ca/sub 0.33/Mn/sub 0.99/Fe/sub 0.01/O/sub 3/

Colossal magnetoresistance (CMR), Mossbauer spectra and neutron diffraction of the iron-doped manganite, La/sub 0.67/Ca/sub 0.33/Mn/sub 0.99//sup 57/Fe/sub 0.01/O/sub 3/, have been studied. The crystal structure is found to be cubic perovskite with the lattice parameter a/sub 0/=3.868 /spl Aring/. It is notable that the Curie temperature, T/sub C/=270 K, line broadening and 1,6 and 3,4 linewidth difference appear to suggest anisotropic hyperfine field fluctuation. The temperature dependence of the effective anisotropy energy is also found to decrease rapidly with increasing temperature.