New vacancied and Dy3+-doped molybdates – Their structure, thermal stability, electrical and magnetic properties. Issue 16 (December 2016)

• Record Type: Journal Article
• Authors: Tomaszewicz, E.; Piątkowska, M.; Pawlikowska, M.; Groń, T.; Oboz, M.; Sawicki, B.; Urbanowicz, P.
• Is Part Of: Ceramics international. Volume 42:Issue 16(2016)
• Page Start: 18357
• Page End: 18367
• Publication Date: 2016-12
• Subjects: A. Powders: solid state reaction -- C. Thermal properties -- C. Magnetic properties -- C. Electrical properties; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2016.08.168
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Microcrystalline samples of new Cd1–3x Dy2x ⌷x MoO4 solid solution with limited homogeneity (0< x ≤0.2222) and cationic vacancies (denoted as ⌷) were prepared by a high-temperature solid state reaction. The XRD data and SEM analysis showed that as-prepared ceramics crystallize in the tetragonal scheelite type symmetry (space group I 41 / a ) with the crystallite size varying between ~2 and ~20 µm. A systematic change in lattice constants, a and c, a s well as in lattice parameter ratio c/a with an increase of Dy content was observed. Dy-doped molybdates are paramagnets with the antiferromagnetic short-range interaction and spin-orbit coupling. Optical and electrical investigations proved Cd1–3x Dy2x ⌷x MoO4 solid solution to be in the insulating state of E g >3 eV at room temperature and the thermally activated conduction of the Arrhenius-type above 350 K. Moreover, the I-V characteristics provided the evidence of symmetrical and non-linear behavior typical of charge carrier emission weakly induced by the temperature. Relative dielectric permittivity ε r below 10 as well as loss tangent tan δ below 0.15 do not substantially depend both on the temperature in the range of 76–400 K and the frequency in the range of 5·10 2 –1·10 6 Hz. These results are interpreted in the framework of the acceptor and donor vacancy centers.