Magnetic resonance study of the Fe+(I) center in SrCl2 single crystals - art. no. 024405

An Fe+-type center with axial (001) symmetry has been studied by electron n uclear double resonance (ENDOR) in the microwave X and Q bands. The Fe+(I) center is produced only after irradiation with x or gamma rays at 80 K of S rCl2:Fe2+ crystals grown in a Cl-2 atmosphere. It has a 3d(7) F-4 Gamma (8) ground state with spin S =3/2. As shown by the correlated analysis of the ENDOR data and electron paramagnetic resonance superhyperfine structure, th e Fe+ ion is situated in the center of a tetragonally compressed cube of ei ght nearest Cl- ions. The simplest model of the Fe+(I) center, compatible w ith the magnetic resonance results, consists of an interstitial Fe+ ion wit h two substitutional monovalent cations, very likely K+ ions, in two opposi te nearest-neighbor Sr2+ sites along the tetragonal axis of the center.