NMRON STUDIES OF THE QUASI-2-DIMENSIONAL FERROMAGNET MN-54-MN(COOCH3)(2)CENTER-DOT-4H2O

Pulsed and continuous wave NMRON, and NMR thermally detected by Nuclea r Orientation have been used to investigate the magnetic properties of the quasi-2-dimensional ferromagnet Mn-54-Mn(COOCH3). 4H(2)O. The NMR frequencies of both the Mn-54 spins and the abundant Mn-55 spins have been determined for the two crystalline lattice sites Mn1 and Mn2. Th e line widths of the Mn-54 resonances are homogeneously broadened to a bout 300 kHz, and the Mn-55 resonances are significantly pulled down i n frequency. The spin-lattice relaxation times in low applied magnetic fields are short with T-1 for the Mn2 site being much less than the v alue for the Mn1 site. Level crossing is observed between the Mn1 and Mn2 resonances in an applied field of 2.6 T.