Date of Award

9-14-2017

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Department of Engineering Physics

First Advisor

John W. McClory, PhD.

Abstract

Spectrometry methods are used to identify and characterize point defects in single crystals of lithium tetraborate (Li2B4O7) and lithium triborate (LiB3O5) doped with silver or copper, and explore the role of these point defects in luminescence. New defects are identified in Ag-doped including: lithium vacancy substitutional-silver-ion defect-pairs (hole trap); isolated lithium vacancies (hole trap); isolated oxygen vacancies (electron trap); interstitial-silver-ion substitutional-silver-ion defect pairs (electron trap); isolated interstitial silver ions (electron trap); and interstitial-silver-ion lithium-vacancy defect pairs (electron trap). Defect models are proposed, and adjustments made to defect models known defects. Defects in Ag-doped LiB3O5 and Cu-doped LiB3O5 are identified including: two species of interstitial-silver-ions (electron traps); isolated-substitutional-silver-ion (hole trap); lithium vacancy substitutional-silver-ion defect pairs (hole trap); interstitial-silver-ion substitutional-silver-ion defect pairs (electron trap); a species of interstitial-copper-ion (electron trap); isolated-substitutional-copper-ion (hole trap); and lithium vacancy substitutional-copper-ion defect pairs (hole trap). Based on this assessment, Ag-doped LiB3O5 is a promising TL and OSL dosimetry material while Cu-doped LiB3O5 is not.

AFIT Designator

AFIT-ENP-DS-17-S-027

DTIC Accession Number

AD1055547

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