EPR OF COPPER IONS IN Pb2MoO5 CRYSTALS
V.A. Nadolinnyi, A.A. Ryadun, V.N. Shlegel', N.V. Ivannikova
Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: ЭПР спектроскопия, кристаллы PbMoO, примесные ионы меди, EPR spectroscopy, PbMoO crystals, impurity copper ions
Abstract
The article presents the results of EPR studies of Pb2MoO5 crystals containing a copper impurity. Based on the analysis of angular dependences of the EPR spectra, it is found that copper ions incorporate into the structure of the Pb2MoO5 crystal in the Cu2+ state and occupy the molybdenum site with the formation of a linear extended Cu(II)-V(O)-Pb(IV) defect along the а axis of the crystal. An oxygen vacancy appears in the structure of the defect to compensate the charge and the lead ion acquires the Pb4+ charge state. According to the structure of this center, one magnetically non-equivalent position with the direction of main values of А and g of A (Cu) zz and gzz tensors parallel to the а axis is observed in the EPR spectra. Moreover, the EPR spectra exhibit an addition hyperfine structure from one lead atom on which the unpaired electron density is 0.061 %. The obtained data on the structure of the defect formed when the copper impurity incorporates into the Pb2MoO5 crystal provided the assumption that the observed light scattering when the light beam is directed perpendicular to the а axis may be due to the cooperative effect of the presence of di- and tetravalent ions substituting for molybdenum in the linear configuration of Pb-O-Mo bonds.
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