Electron and hole traps in Ag-doped lithium tetraborate (Li2B4O7) crystals

Brant, A. T.; Kananan, B. E.; Murari, Madhav K.; McClory, John W.; Petrosky, James C.; Адамів, В.Т.; Bürak, Ya. I.; Dowben, Peter A.; Halliburton, L. E.

doi:10.1063/1.3658264

Cited by 44 publications

(20 citation statements)

References 36 publications

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“…This defect is formed during the x-ray irradiation when an interstitial Ag þ (4d 10 ) ion traps an electron and becomes a Ag 0 (4d 10 5s 1 ) center. As described previously [6], the trapped-electron spectrum in Fig. 5(a) has 16 lines because of resolved hyperfine interactions with 107 Ag and 109 Ag nuclei and one additional I ¼ 3/2 nucleus.…”

Section: Electron Paramagnetic Resonance (Epr)mentioning

confidence: 94%

“…These trapped hole centers are formed when Ag þ (4d 10 ) ions at Li þ sites trap the radiation-induced holes and become Ag 2 þ (4d 9 ) ions. Direct evidence that the two EPR spectra represent Ag 2 þ ions comes from their large positive g shifts, their small hyperfine splittings, and the unambiguous electron-nuclear double resonance (ENDOR) identification of 107 Ag and 109 Ag as the nuclei responsible for the hyperfine splittings [6]. In previous papers [6,13], these trapped-hole centers were simply labeled Center A and Center B, respectively.…”

Section: Electron Paramagnetic Resonance (Epr)mentioning

confidence: 98%

“…Two trapped-hole centers and one trapped-electron center, each with an unpaired spin, are formed when our Ag-doped Li 2 B 4 O 7 crystal is irradiated at room temperature with x rays [6,13]. Fig.…”

Section: Electron Paramagnetic Resonance (Epr)mentioning

confidence: 99%

“…The primary focus thus far has been on the thermoluminescence (TL) properties of Li 2 B 4 O 7 [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Only recently has optically stimulated luminescence (OSL) been reported from this material [16][17][18][19].…”

Section: Introductionmentioning

confidence: 98%

“…These TL and OSL investigations have shown that light emission is greatly enhanced when Li 2 B 4 O 7 is doped with either Cu þ or Ag þ ions. These monovalent dopants are unique in Li 2 B 4 O 7 , as they serve as both a hole trap and an electron trap during exposures to ionizing radiation [6,11]. When substituting for Li þ ions, the Cu þ and Ag þ ions trap holes and become Cu 2 þ and Ag 2 þ ions.…”

Section: Introductionmentioning

confidence: 99%

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Optically stimulated luminescence (OSL) from Ag-doped Li2B4O7 crystals

Kananen

Maniego

Golden

et al. 2016

Journal of Luminescence

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a b s t r a c tOptically stimulated luminescence (CW-OSL) is observed from Ag-doped lithium tetraborate (Li 2 B 4 O 7 ) crystals. Photoluminescence, optical absorption, and electron paramagnetic resonance (EPR) are used to identify the defects participating in the OSL process. As-grown crystals have Ag þ ions substituting for Li þ ions. They also have Ag þ ions occupying interstitial sites. During a room-temperature exposure to ionizing radiation, holes are trapped at the Ag þ ions that replace Li þ ions and electrons are trapped at the interstitial Ag þ ions, i.e., the radiation forms Ag 2 þ (4d 9 ) ions and Ag 0 (4d 10 5s 1 ) atoms. These Ag 2 þ and Ag 0 centers have characteristic EPR spectra. The Ag 0 centers also have a broad optical absorption band peaking near 370 nm. An OSL response is observed when the stimulation wavelength overlaps this absorption band. Specifically, stimulation with 400 nm light produces an intense OSL response when emission is monitored near 270 nm. Electrons optically released from the Ag 0 centers recombine with holes trapped at Ag 2 þ ions to produce the ultraviolet emission. The OSL response is progressively smaller as the stimulation light is moved to longer wavelengths (i.e., away from the 370 nm peak of the absorption band of the Ag 0 electron traps). Oxygen vacancies are also present in the Ag-doped Li 2 B 4 O 7 crystals, and their role in the OSL process as a secondary relatively short-lived electron trap is described.

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Section: Electron Paramagnetic Resonance (Epr)mentioning

confidence: 94%

Section: Electron Paramagnetic Resonance (Epr)mentioning

confidence: 98%

Section: Electron Paramagnetic Resonance (Epr)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

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Optically stimulated luminescence (OSL) from Ag-doped Li2B4O7 crystals

Kananen

Maniego

Golden

et al. 2016

Journal of Luminescence

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EXAFS and EPR analysis of the local structure of Mn‐doped Li₂B₄O₇

Kelly

Kong

Buchanan

et al. 2013

Physica Status Solidi (b)

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The local structure of Mn-doped Li 2 B 4 O 7 (001) was investigated using extended X-ray absorption fine structure (EXAFS) at the Mn K edge and electron paramagnetic resonance (EPR). The location of the Mn dopant in a lithium tetraborate crystal is consistent with occupation of a site with strong oxygen coordination. The Mn-O bond lengths are similar to those observed with Mn doping of the icosahedral based boron carbide where Mn is in a substitutional dopant in one of the cage sites. From EXAFS, the manganese does not appear to greatly alter the overall tetragonal form of lithium tetraborate, with the dopant most likely substituting for one of the two B sites and with placement of some of the Mn in a Li site still possible. The EPR spectra agree with the literature examined resolving multiple Mn species in the crystal lattice.

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