| Autor: |
Hong, Wei, Halliburton, L. E., Stevens, K. T., Perlov, D., Catella, G. C., Route, R. K., Feigelson, R. S. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 8/15/2003, Vol. 94 Issue 4, p2510-2515, 6p, 4 Graphs |
| Abstrakt: |
Electron paramagnetic resonance (EPR) has been used to investigate point defects in single crystals of β-BaB[SUB2]O[SUB4] (commonly referred to as BBO). An irradiation with x rays at 77 K produces two dominant EPR spectra, one electron like and the other holelike. The trapped-electron center exhibits a 16-line hyperfine pattern from two boron nuclei. With the magnetic field parallel to the c axis, its g value is 1.9993 and the [SUP11]B hyperfine splitting are 49 and 42 G. We suggest that this defect is an oxygen vacancy with a trapped electron nearly equally shared by the two neighboring boron ions. In contrast, the trapped-hole center exhibits a four-line hyperfine pattern due to one boron, and is assigned to a hole localized on a nonbridging oxygen ion with no other defects nearby (i.e., a self-trapped hole). With the magnetic field along the c axis, this center has a g value of 2.0113 and a [SUP11]B hyperfine splitting of 14.1 G. Warming the crystal to temperatures between 80 and 90 K destroys the initial four-line hole spectrum and introduces other hole centers (most likely perturbed by nearby Na[SUP+] ions substituting for Ba[SUP2+] ions or by barium vacancies). These electron and hole traps are expected to play a role in the response of BBO crystals to high-power pulsed ultraviolet lasers. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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