Mössbauer Study of Fe²⁺ in the Low Temperature Phase of Fe₃O₄

Abstract

Mössbauer spectra of the low temperature phase of single crystal magnetite were measured with a magnetic field along various directions in (1\bar10) plane after cooled in the magnetic field along [112]. Measured spectra were found to be sensitive to the direction of the applied magnetic field. As the result of detailed analysis two kinds of Fe²⁺ ions (Fe²⁺–I and II) were clearly recognized and the principal Z-axis of EFG was found to be along [100] or [010] for Fe²⁺–I and [001] for Fe²⁺–II. Since the observed anisotropy of the internal magnetic field is well described by EFG observed, angular momentum of each Fe²⁺ ion is suggested to be quenched.