Journal of Crystal Growth, Vol.311, No.23-24, 4670-4674, 2009
High temperature transformation in the defects and impurities system of PbTe:Eu crystals
High temperature transformations in the defects and impurities system of PbTe:Eu crystals grown from the melt by Bridgman method are investigated. Studies of magnetic susceptibility (MS) of the crystals annealed in vacuum at the temperature of 913 K were used for this purpose. It is established that some complexes, which feel ferromagnetic ordering below 75-80 K, are formed in the PbTe:Eu crystals in process of crystal growth. It is concluded that the agglomerations based on the europium oxide EuO form these complexes. Correlations are revealed between transformations in both systems of Eu impurities and non-point native defects like Te precipitates under the effect of high-temperature annealing. A mechanism of transformations explaining the presence and behavior of the correlations is proposed. (C) 2009 Elsevier B.V. All rights reserved.