Dynamics of negatively charged divacancies in neutron irradiated type Ib diamond
| Autor: | M. J. R. Hoch, J.K. Kirui, J. A. Van Wyk |
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| Rok vydání: | 2013 |
| Předmět: |
Condensed matter physics
Phonon Chemistry Mechanical Engineering Diamond General Chemistry engineering.material Neutron temperature Electronic Optical and Magnetic Materials law.invention Paramagnetism Laser linewidth law Materials Chemistry engineering Neutron Irradiation Electrical and Electronic Engineering Atomic physics Electron paramagnetic resonance |
| Zdroj: | Diamond and Related Materials. 39:78-81 |
| ISSN: | 0925-9635 |
| DOI: | 10.1016/j.diamond.2013.08.003 |
| Popis: | Thermal neutron irradiation of synthetic type Ib diamond, followed by annealing, results in a number of paramagnetic point defect centers. One of these is the composite defect designated W29. Previous EPR measurements have shown that the W29 center (S = 3/2) is a charged divacancy [VV]− with spin Hamiltonian parameters similar to those of the R4/W6 neutral divacancy center [VV]0 (S = 1) found in irradiated high purity type IIa diamond. The present EPR linewidth and spin-lattice relaxation rate measurements, made as a function of temperature on the W29 center, show that an Orbach two-phonon process, with a gap of ~ 20 meV, plays a dominant role in determining the relaxation behavior above 20 K. Below 20 K a direct single phonon process provides the spin-lattice relaxation mechanism and the relaxation times become long, of the order of milliseconds. The linewidth behavior with temperature is accounted for in terms of changes in the spin dynamics. |
| Databáze: | OpenAIRE |
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