Magnetic and Electrical Characteristics of Nd 3+ -Doped Lead Molybdato-Tungstate Single Crystals.

Single crystals of Pb▯Nd(MoO)(WO) (PNMWO) with scheelite-type structure, where ▯ denotes cationic vacancies, have been successfully grown by the Czochralski method in air and under 1 MPa. This paper presents the results of structural, optical, magnetic and electrical, as well as the broadband dielectric spectroscopy measurements of PNMWO single crystals. Research has shown that replacing diamagnetic Pb ions with paramagnetic Nd ones, with a content not exceeding 0.01 and possessing a screened 4-shell, revealed a significant effect of orbital diamagnetism and Van Vleck's paramagnetism, -type electrical conductivity with an activation energy of 0.7 eV in the intrinsic area, a strong increase of the power factor above room temperature for a crystal with = 0.005, constant dielectric value (~30) and loss tangent (~0.01) up to room temperature. The Fermi energy (~0.04 eV) and the Fermi temperature (~500 K) determined from the diffusion component of thermopower showed shallow donor levels.