Wydział Chemii

Tadeusz Groń

M. Maciejkowicz

Elżbieta Tomaszewicz

Małgorzata Guzik

Monika Oboz

Bogdan Sawicki

Sebastian Pawlus

A. Nowok

Z. Kukuła

2020

Journal of Advanced Ceramics

9

255-268

10.1007/s40145-020-0366-9

Naukowa

Angielski

Artykuł

Gd3+-doped lead molybdato–tungstates with the chemical formula of Pb1–3x Gd2x(MoO4)1–3x(WO4)3x (where x = 0.0455, 0.0839, 0.1430, corresponding to 9.53, 18.32, 33.37 mol% of Gd3+, respectively, as well as denotes cationic vacancies) were successfully synthesized via combustion route. The XRD and SEM results confirmed the formation of single-phase, tetragonal scheelite-type materials (space group I41/a) with the uniform, spherical and oval grains ranging from 5 to 20 m. Individual grains are strongly agglomerated into big clusters with the size even above 50 m. The magnetic measurements as well as the Brillouin fitting procedure showed paramagnetic state with characteristic superparamagnetic-like behaviour and the short-range ferromagnetic interactions. The electrical and broadband dielectric spectroscopy studies revealed insulating properties with the residual electrical n-type conduction of 2×10–9 S/m and low energy loss (tan 0.01) below 300 K. Dielectric analysis showed that no dipole relaxation processes in the Gd3+-doped materials were observed. A fit of dielectric loss spectra of Gd3+-doped samples by sum of the conductivity and the Havriliak–Negami, Cole–Cole, and Cole–Davidson functions confirmed this effect.

scheelite, Gd 3+ -substituted PbMoO 4, combustion, solid solution, magnetic properties, dielectric properties

CC-BY

http://dx.doi.org/10.1007/s40145-020-0366-9

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