title: Exchange-mediated spin-lattice relaxation of Fe3+ ions in borate glasses.
abstract: Spin-lattice relaxation times (T1) of two borate glasses doped with different concentrations of Fe2O3 were measured using the Electron Spin-Echo (ESE) technique at X-band (9.630 GHz) in the temperature range 2-6K. In comparison with a previous investigation of Fe3+-doped silicate glasses, the relaxation rates were comparable and differed by no more than a factor of two. The data presented here extend those previously reported for borate glasses in the 10-250K range but measured using the amplitude-modulation technique. The T1 values were found to depend on temperature (T) as T(n) with n approximately 1 for the 1% and 0.1% Fe2O3-doped glass samples. These results are consistent with spin-lattice relaxation as effected by exchange interaction of a Fe3+ spin exchange-coupled to another Fe3+ spin in an amorphous material.
authors.affiliation: Physics Department, Concordia University, 1455 de Maisonneuve Boulevard West, Montreal, Que., Canada H3G 1M8. skmisra@alcor.concordia.ca
authors.forename: Sushil K
authors.initials: SK
authors.lastname: Misra
authors.forename: John R
authors.initials: JR
authors.lastname: Pilbrow
mesh_terms: D000465:Algorithms; D001881:Borates / Q000737:chemistry*; D003198:Computer Simulation; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005898:Glass / Q000737:chemistry*; D007477:Ions; D007501:Iron / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D044367:Phase Transition; D013113:Spin Labels
chemical_list: D001881:Borates; D007477:Ions; D013113:Spin Labels; D007501:Iron