A multi-frequency EPR spectroscopy approach in the detection of boson peak excitations

作者:Kveder Marina*; Merunka Dalibor; Ilakovac Amon; Rakvin Boris
来源:Journal of Magnetic Resonance, 2011, 213(1): 26-31.
DOI:10.1016/j.jmr.2011.08.029

摘要

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.

  • 出版日期2011-12