Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2010.3367.3373HassanMahmoud A. JafarMousa M. MatuchovaMarie BulosBasim N. 1220101024The wide-bandgap and highly-resistive lead iodide (PbI2) crystalline semiconductor has been considered as a promising room-temperature nuclear radiation detector in environmental applications. The PbI2 single crystals yet grown, however, suffer from problems of phase transformation among its diverse polytypic modifications and formation of polytypes admixture during growth or under post-growth working conditions and from the presence of structural defects and native impurities that normally cause notable deterioration in the performance of devices integrating them. The behaviour of experimental dielectric constant ε1 of undoped melt-grown 2H-polyttype PbI2 single crystals with isothermal annealing temperature Ta (≤94°C) may be taken as a sign for the occurrence of a reversible 2HX12R phase transition in them. However, the effect of reducing the amount of structural native defects and imperfections in such undoped PbI2 crystals by thermal annealing cannot be entirely excluded. The measured room temperature value of ε1 at 1 kHz (~6.5 for Ta = 94°C) of these PbI2 single crystals is compatible with the findings of theoretical dielectric functions model and is consistent with experimental values of ε1 reported by other workers for melt- and gel-grown PbI2 single crystals.]]>Shah, K.S., P. Bennett, M. Klugerman, L. Moy and L. Cirignano et al.,199744448450Deich, V. and M. Roth,1996380169172Hermon, H., R.B. James, J. Lund, E. Cross and A. Antolak et al.,1998487361368Shoji, T., K. Hitomi, T. Tiba, T. Suehiro and Y. Hiratate,19982 crystal and its response characteristics for Gamma-rays.]]>45581584He, Y., S. Zhu, B. Zhao, Y. Jin, Z. He and B. Chen,20072 single crystals.]]>300448451Hayashi, T., M. Kinpara, J.F. Wang, K. Mimura and M. Isshiki,20082 single crystals from stoichiometric and Pb excess melts.]]>3104750Matuchova, M., K. Zdansky, J. Zavadil, J. Tonn and M.M. Abdul-Gader Jafar et al.,201031212331239Matuchova, M., K. Zdansky, J. Zavadil, J. Maixner, D. Alexiev and O. Prochazkova,20069394398Matuchova, M., K. Zdansky and J. Zavadil,20091656063Matuchova, M., O. Prochazkova, J. Maixner, K. Zdansky and J. Zavadil,2005212751279Matuchova, M., K. Zdansky, J. Zavadil, A. Danilewsky and F. Riesz et al.,200931135573562Hassan, M.A. and M.M. Abdul-Gader Jafar,2006566526535Jafar, M.M.A.G., M.A. Hassan, I.F. Al-Hamarneh and M. Matuchova,20092009pp: 98102Yadav, D.P., K.V. Rao and H.N. Acharya,19802 single crystals.]]>60273276Dugan, A.E. and H.K. Henisch,196728971976Zallen, R. and M.L. Slade,19752.]]>1715611566Jain, A. and G.C. Trigunayat,19962 crystals.]]>52590595Choudhary, S.K. and G.C. Trigunayat,19892 crystals.]]>16425430Blonskii, I.B., L.V. Mizrukhin and V.V. Tishenko,19802 by the exciton spectroscopic method.]]>57K113K117Konings, R.J.M., E.H.P. Cordfunke and R.R. van der Laan,19952: Evidence for a reversible polytypic transition.]]>2308588Pałosz, B.,19832 II. Clasification of faults and structural series of polytypes; Conditions of polytypic growth of CdI2, PbI2, CdBr2, SnS2, SnSe2 and Ti1.2S2.]]>801141Rao, M. and O.N. Srivastava,197811919926Salje, E., B. Palosz and B. Wruck,1987In situ observation of the polytypic phase transition 2H-12R in PbI2: Investigations of the thermodynamic, structural and dielectric properties.]]>2040774096Bibik, V.A., I.B. Blonskii, M.S. Brodin and N.A. Davydova,19852 induced by laser irradiation.]]>90K11K14Shah, M.A. and M.A. Wahab,20001918131816Raw, A.S., M.S. Furness, D.S. Gill, R.C. Adams, F.O. Holcombe Jr. and L.X. Yu,200456397414Saddow, S.E. and A. Agarwal,2004Adolph, B., K. Tenelsen, V.I. Gavrilenko and F. Bechstedt,19975514221429Ahuja, R., H. Arwin, A.F. Silva, C. Persson and J.M. Osorio-Guillen et al.,20029272197224Palosz, B., W. Steurer and H. Schulz,19902 polytypes 2H and 4H: A study of the 2H-4H transition.]]>252855295