Magnetic and Electrical Characteristics of Nd3+-Doped Lead Molybdato-Tungstate Single Crystals

Bogdan Sawicki; Elżbieta Tomaszewicz; Tadeusz Groń; Monika Oboz; Joachim Kusz; Marek Berkowski

doi:10.3390/ma16020620

Magnetic and Electrical Characteristics of Nd³⁺-Doped Lead Molybdato-Tungstate Single Crystals

Materials (Basel). 2023 Jan 9;16(2):620. doi: 10.3390/ma16020620.

Authors

Bogdan Sawicki¹, Elżbieta Tomaszewicz², Tadeusz Groń¹, Monika Oboz¹, Joachim Kusz¹, Marek Berkowski³

Affiliations

¹ Institute of Physics, University of Silesia in Katowice, 40-007 Katowice, Poland.
² Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, 70-310 Szczecin, Poland.
³ Institute of Physics, Polish Academy of Sciences, 02-668 Warszawa, Poland.

Abstract

Single crystals of Pb_1-3x▯_xNd_2x(MoO₄)_1-3x(WO₄)_3x (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 Pb²⁺ ions with paramagnetic Nd³⁺ ones, with a content not exceeding 0.01 and possessing a screened 4f-shell, revealed a significant effect of orbital diamagnetism and Van Vleck's paramagnetism, n-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 x = 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.

Keywords: dielectric spectroscopy; electrical conductivity; magnetic properties; power factor; single crystals.

Grants and funding

This research received no external funding.