Superscript60/SuperscriptCo Gamma Irradiation

Authors: Thankamma George A G Kunjomana

Publish Date: 2015/02/15

Volume: 28, Issue: 5, Pages: 559-566

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Abstract

Physical vapor deposition method was employed to deposit antimony telluride Sb2Te3 crystals in a dualzone furnace The microstructure surface topography and composition of samples were characterized using Xray diffraction atomic force and scanning electron microscopy Seebeck coefficient S⊥c electrical conductivity σ⊥c as well as power factor PF were enhanced for pure Sb2Te3 samples upon annealing and the samples annealed at 473 K exhibited the highest PF of 316 × 10−3 W m−1K−2 with an enhancement of 22 in the figure of merit Z When the delivered dose of 60Co gamma radiation was increased from 0 to 30 kGy in the stoichiometric crystals σ⊥c decreased due to the decrease in mobility As a result of the increase in S PF and Z improved by 1211 and 137 respectively in the 30 kGy gammairradiated crystals Both R H Bc and S⊥c were positive suggesting that the prepared Sb2Te3 crystals retained the ptype semiconductivity after these treatmentsOne of the authors G Thankamma acknowledges gratitude to the management of Jyoti Nivas College Autonomous Bangalore for the support in pursuing this research work The authors are thankful to Microtrol Sterilization Services Pvt Ltd Jigani Bangalore for the gamma ray irradiation process and Chairman Materials Research Center Indian Institute of Science Bangalore for various characterizations

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