MOSSBAUER STUDY OF IRON-DOPED LITHIUM-NIOBATE

From Mossbauer spectra of LiNbO3:Fe-57(III) single crystals under exte rnal fields of 4.92 and 6.2 T, the crystal field and hyperfine paramet ers are determined. Transmission integral fits indicate a Boltzmann po pulation of the Fe(III) electronic levels with a spin temperature equa l to the sample temperature. Spectra at external fields of OT and 19 m T can be satisfactorily simulated using an effective spin 1/2, g-facto rs calculated from spin-expectation values and an internal averaged di pole field of 5.5 mT inclined 20 degrees to the c-axis. The simulation s indicate cross-relaxation between Nb and Li nuclear spins and the Fe (III) electronic spin.