Short Notes K79 phys. stat. sol. (b) zyxwv -9 122 K79 (1984) Subject classification: 20.3; 22.5.2 Department of Physics, Nagpur University 1) Study of Annealing and Deformation Effect on TL of NaC1:KCl BY R.B. PODE and B. T zyxwvu . DESHMUKH Various annealing and preheat treatments are known to affect the glow curves profoundly. While studying the TL of doped crystal, it is therefore essential to study the effect of annealing since impurities may form aggregates, complexes, or even precipitates zyxwvu /l/. Experiments on the effect of plastic deformation on TL would be very interesting. However, the effect of deformations on TL is not at all clear. The effect of plastic deformation on TL of pure and doped alkali halides has been studied by a number of workers /2 to 6/. Clark and Newman have observed deformation-induced glow peaks at higher temperature in KC1 crystals /7/. Kamavisdar and Deshmukh reported a broadening and shifting of the Z1 centre glow peak to lower temperature as a result of interaction with dis- locations inherent in the microcrystalline powder of KC1 /8/. However, Moharil observed no change in the Z centre glow peak position of annealed crystals and its powder /9/. In the present investigations the effect of annealing and defor- mation on TL of NaC1:KCl is studied to reveal the exact origin of the above pro- cesses. zyxwvut 1 The crystals of NaC1:KCl (5 mol% KC1) were grown from the melt by the Kyropoulos method. G.R grade powders were used as starting material. Thin slices (1Ox5xO.4 mm ) were cleaved from the same as-grown block and coloured at 300 K by exposing them to r-rays from a 6oCo source for a dose of 2x10 R. The crystals were crushed to obtain microcrystalline powders (80 to 100 mesh) and exposed to the same x-ray dose as the crystals. The samples were heated at a linear rate of 50 K/min using a Powertech temperature controller pro- grammer. The emission from the crystals was detected by a RCA 931 zy A photo- multiplier and recorded on a millivolt recorder. Details of the experimental set- up can be found elsewhere /1 O/. The optical absorption and reflectance spectra of crystals and powders, respectively, at 300 K were recorded on a CZ spectro- photometer. The crystals were annealed in a standard furnace with temperature controller programmer with an accuracy of +2 3 5 zy 0 C. - 1 ) Nagpur 440010, India.