UV irradiation eff ect on the electrical properties of Pb2MoO5 single crystal
Abstract
Electrical properties of double lead molybdate Pb2MoO5 single crystal were studied in AC fi eld (f=1 kHz) after irradiation with UV light (290 K). It was found that UV irradiation caused appearance of maximums on permittivity ε and conductivity σ temperature dependences, which were observed around 530 K. The anomalies of ε and σ vanished after annealing at 700 K and could be restored by subsequent UV irradiation performed at room temperature. The magnitude of ε and σ peaks increased for higher exposition time. Above 600 K conductivity σ was practically independent on irradiation. It is proposed that photoelectrons induced by UV light, are trapped by Mo located within the oxygen tetrahedrons with vacancy VO in one of the vertexes. The dipole moments of (MoO3)- groups reorient at VO hopping through the tetrahedron vertexes. Annealing at 700 K thermally decomposes (MoO3)- complexes. For T > 600 K behavior of σ(T) is determined by conduction currents and nearly insensitive to UV irradiation. At high temperatures the photoelectrons do not contribute to conductivity since they are bound in (MoO3)- centers, recombine with holes or re-captured by more deep traps.
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A.Yu. Tchernyatin. Proc. of SPIE, 5953, 59530U-1(2005).
N. Uchida, Sh. Miyazawa. J. Opt. Soc. Of America, 60, 1375 (1970).
M.G. Mil’kov, M.D. Volnianskii, А.М. Antonenko, V.B. Voloshinov. Akusticheskij Zhurnal (in Russian), 58, 2, 206 (2012).
M.P. Trubitsyn, I.P. Volnyanskaya. Vìsnik Dnìpropetrovs’kogo unìversitetu. Serìâ Fìzika, radìoelektronika, 17, 16, 70 (2009).
S. Nedilko, V. Chornii, Yu. Hizhnyi, M. Trubitsyn, I. Volnyanskaya. Optical Materials, 36, 1754 (2014).
I.P. Volnyanskaya, S.G. Nedel’ko, Yu.A. Khizhnyi, V.P. Chornii, M.P. Trubitsyn, D.S. Bondar. Phys. of the Solid State, 57, 7, 1399 (2015).
A.M. Antonenko, M.D. Volnianskiy, A.A. Krutko, O.D.Makarov. Abstract book of the Intern. Conf. “Crystal Materials 2005”. Kharkov (Ukraine), 93 (2005).
S. Miyazawa, H. Iwasaki. J. Crystal Growth, 8, 359 (1971).
B.F. Mentzen, A. Latrach, J. Bouix, A.W. Hewat. Mater. Res. Bull., 19, 549 (1984).
M. Buryi, V. Laguta, M. Fasoli, F. Moretti, M. Trubitsyn, M. Volnianskii, A. Vedda, M. Nikl. J. of Luminescence, 192, 767 (2017).
V.V. Laguta, J. Rosa, M.I. Zaritskii, M. Nikl, Y. Usuki. J. Phys.: Condens. Matter, 10, 7293 (1998).
V.V. Laguta, M. Martini, A. Vedda, Rosetta E., M. Nikl, E. Mihóková, J. Rosa, Y. Usuki. Phys. Rev., B 67, 205102-1-8 (2003).
V.V. Laguta, A. Vedda, D. Di Martino, M. Martini, M. Nikl, E. Mihóková, J. Rosa, Y. Usuki. Phys. Rev., B71, 235108-1-10 (2005).