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Title: Gallium hole traps in irradiated KTiOPO{sub 4}:Ga crystals

Nominally pure and gallium doped single crystals of potassium titanyl phosphate (KTiOPO{sub 4}) have been studied by Electron Paramagnetic Resonance at low temperatures before and after irradiation. Irradiation with 20 MeV electrons performed at room temperature and liquid nitrogen temperature caused an appearance of electrons and holes. Gallium impurities act as hole traps in KTiOPO{sub 4} creating Ga{sup 4+} centers. Two different Ga{sup 4+} centers were observed, Ga1 and Ga2. The Ga1 centers are dominant in Ga-doped samples. For the Ga1 center, a superhyperfine structure with one nucleus with nuclear spin ½ was registered and attributed to the interaction of gallium electrons with a phosphorus nucleus or proton in its surrounding. In both Ga1 and Ga2 centers, Ga{sup 4+} ions substitute for Ti{sup 4+} ions, but with a preference to one of two electrically distinct crystallographic positions (site selective substitution). The Ga doping eliminates one of the shortcomings of KTP crystals—ionic conductivity of bulk crystals. However, this does not improve significantly the resistance of the crystals to electron and γ-radiation.
Authors:
; ;  [1] ;  [2]
  1. Physics Department, Montana State University, Bozeman, Montana 59717 (United States)
  2. Idaho Accelerator Center, Idaho State University, Pocatello, Idaho 83209 (United States)
Publication Date:
OSTI Identifier:
22402732
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 21; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CRYSTALLOGRAPHY; DOPED MATERIALS; ELECTRON SPIN RESONANCE; ELECTRONS; GALLIUM; IMPURITIES; IONIC CONDUCTIVITY; IRRADIATION; MEV RANGE 10-100; MONOCRYSTALS; PHOSPHATES; SPIN; TITANIUM IONS