Mn55 Nuclear Magnetic Resonance in Manganese Ferrite

Abstract

The observation of the nuclear magnetic resonance of Mn55 in ferromagnetic MnFe2O4 is reported. The resonance frequency in a sphere is 586.0 Mc in an external field of 2730 Oe; and the linewidth is found to vary from 1.7 Mc at 1.65°K to 2.2 Mc at 4.2°K. The nuclei involved have been identified as associated with Mn2+ ions located on A sites in the spinel lattice. The double resonance technique used in these experiments allows the direct measurement of the nuclear spin-lattice relaxation time T1. The magnitude of T1 at 1.65°K is found to be 1.5×10−3 sec.