title: A variable temperature EPR study of Mn(2+)-doped NH(4)Cl(0.9)I(0.1) single crystal at 170 GHz: zero-field splitting parameter and its absolute sign.
abstract: EPR measurements have been carried out on a single crystal of Mn(2+)-doped NH(4)Cl(0.9)I(0.1) at 170-GHz in the temperature range of 312-4.2K. The spectra have been analyzed (i) to estimate the spin-Hamiltonian parameters; (ii) to study the temperature variation of the zero-field splitting (ZFS) parameter; (iii) to confirm the negative absolute sign of the ZFS parameter unequivocally from the temperature-dependent relative intensities of hyperfine sextets at temperatures below 10K; and (iv) to detect the occurrence of a structural phase transition at 4.35K from the change in the structure of the EPR lines with temperature below 10K.
authors.affiliation: Physics Department, Concordia University, Montreal, Que., Canada H3G 1M8. skmisra@vax2.concordia.ca
authors.forename: Sushil K
authors.initials: SK
authors.lastname: Misra
authors.forename: Serguei I
authors.initials: SI
authors.lastname: Andronenko
authors.forename: Prem
authors.initials: P
authors.lastname: Chand
authors.forename: Keith A
authors.initials: KA
authors.lastname: Earle
authors.forename: Sergei V
authors.initials: SV
authors.lastname: Paschenko
authors.forename: Jack H
authors.initials: JH
authors.lastname: Freed
mesh_terms: D000643:Ammonium Chloride / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D008345:Manganese; D044367:Phase Transition; D013696:Temperature
chemical_list: D000643:Ammonium Chloride; D008345:Manganese