title: A multi-frequency EPR spectroscopy approach in the detection of boson peak excitations.
abstract: The influence of boson peak (BP) excitations on low-temperature spin-lattice relaxation rate of a paramagnetic center embedded in a glassy matrix is investigated in the context of multi-frequency electron paramagnetic resonance (EPR) detection. In the theoretical analysis, the transition rate of spin one-half in the presence of a phonon field is calculated within the approximation of Fermi's golden rule. Several phonon densities of states are compared, among which one originating from a model of quasi-localized vibrations has been introduced into electron spin relaxation formalism for the first time. The respective frequency dependencies of spin-lattice relaxation rates are predicted which should lead to observable effects of BP modes if a multi-frequency study at very low temperatures is performed.
authors.affiliation: Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia. kveder@irb.hr
authors.forename: Marina
authors.initials: M
authors.lastname: Kveder
authors.forename: Dalibor
authors.initials: D
authors.lastname: Merunka
authors.forename: Amon
authors.initials: A
authors.lastname: Ilakovac
authors.forename: Boris
authors.initials: B
authors.lastname: Rakvin
mesh_terms: D000465:Algorithms; D003080:Cold Temperature; D003460:Crystallization; D004574:Electromagnetic Fields; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005898:Glass / Q000737:chemistry*; D016014:Linear Models; D015233:Models, Statistical; D013113:Spin Labels; D013816:Thermodynamics
chemical_list: D013113:Spin Labels