NMR study in a half-metallic system, Sr2FeMoO6

Abstract Mo-NMR measurements have been carried out for a half-metallic compound, Sr 2 FeMoO 6 , which involves a highly polarized conduction band consisting of Mo-4d, Fe-3d, and O-2p electrons. The spin-lattice relaxation of the Mo nuclei was measured in zero magnetic field as well as an applied field. Two relaxation components come from the in-domain and domain-wall fluctuations are found in zero field. The former (in-domain) component is specified with a single spin-lattice relaxation rate 1 / T 1 showing a Korringa-like temperature T dependence ( 1 / TT 1 = const . ) at low temperatures, which reflects the itinerant character of the 4d electrons. A fraction of the latter component is strongly suppressed with an applied field, which is consistent with the easy domain-wall control by the magnetic field.