Zero-field {mu}{sup +}SR study of the collossal magnetoresistance material La{sub 0.67}Ca{sub 0.33}MnO{sub 3}

Zero-field {mu}{sup +}SR and resistivity experiments on La{sub 0. 67}Ca{sub 0.33}MnO{sub 3} powder shows that the ferromagnetic transition temperature (Tc = 274 K) and resistivity peak temperature coincide to within 1K, about 10 K higher that T{sub c} determined from the bulk magnetization. The sublattice magnetization v{sub mu}(T) is well described for T {<=} T{sub c} by (1-T/T{sub c}){sup beta}, where {beta} = 0.345 {+-} 0.015. Unusual relaxational dynamics suggest a wide distribution of Mn-ion correlation times. These results are discussed in terms of the effects of polarons on the spin and charge dynamics.