FIZIKA A 18 (2009) 1 , 19-28

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KINETIC BEHAVIOUR OF F-CENTRES UNDER THERMAL STRESS

SWARUPA BANDYOPADHYAYa, TANUSRI GHOSHa, KAMAL KANTI RAYa, SATYAJIT KARa,
ANJAN KUMAR LAHIRIa, AJAY KUMAR MAITIb and KUSHALENDU GOSWAMIa
aDepartment of Physics, Jadavpur University, Kolkata 700 032, India
bBidhannagar College (Govt. of West Bengal), Salt Lake City, Kolkata 700 064, India

Received 17 January 2008;  Accepted 15 April 2009
Online 21 May 2009

The migration of colour clouds after the electron injection in pure and doped KCl and KBr alkali halides under thermal and field stresses is studied with an anode contact of spherical geometry. The diffusion coefficient of the colour clouds has been obtained using a derived analytical expression and the experimental data, and the activation energy of the colour centre was estimated. The dissociation energy values under thermal and field stresses for doped crystals are deduced through the mobility transport equation. The results indicate the effect of doping in an otherwise pure counterpart of the same crystals.

 PACS numbers: 61.72.Ww, 61.72.Ji
UDC 538.958, 538.935

Keywords: alkali halides with doping-induced defects, diffusion coefficient, thermal stress, mobility of F-centres, activation energy, space-charge limited conduction

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