NMR study of double perovskite Sr2FeMoO6

The NMR spin-echo spectra measured on a powder sample of Sr2FeMoO6 at 3 and 77 K at zero field and in an applied magnetic field are reported. The main resonance line at 68.5 MHz in zero magnetic field at 3 K is identified Lis originating from Mo-95 and Mo-97. The resonance frequency and its shift in the applied field correspond to a hyperfine field of 24T at the Mo nucleus. parallel to the magnetisation. This large field indicates the presence of a magnetic moment of the order of 0.6 mu(B) at the Mo site antiparallel to he Fe moments. The relation of the results to the magnetoresistive properties of the material is discussed. (C) 2002 Elsevier Science B.V. All rights reserved.