Electrical Properties of Tungstates Ln2(WO4)3 (Ln – Gd, Ho)
Electrical properties of Gd2(WO4)3 and Ho2(WO4)3 were studied and the type of charge carriers was determined. The studied compounds have a salt-like isle structure with isolated tetrahedrons. It crystallises in the Еu2(WO4)3 structural type, so-called ‘defective scheelite’, in which 1/3 of Ln sites are vacant, Ln2/3[VLn]1/3WO4. Predominant ionic conductivity in Ln2(WO4)3 (Ln = Gd, Ho) was established both by the EMF method and from independence of conductivity versus oxygen partial pressure. A minor contribution (4-11%) of the anion [WO4]2- transport was detected by the Tubandt method, which along with the results of the EMF technique proves the predominant oxygen conductivity.
 Y. Zhou, S. Adams, R. P. Rao, D. D. Edwards, A. Neiman, and N. Pestereva, Charge transport by polyatomic anion diffusion in Sc2(WO 4)3, Chemistry of Materials, 20, no. 20, 6335–6345, (2008).
 A. Y. Neiman, N. N. Pestereva, Y. Zhou, D. O. Nechaev, E. A. Koteneva, K. Vanec, B. Higgins, N. A. Volkova, and I. G. Korchuganova, The nature and the mechanism of ion transfer in tungstates Me 2+WO4 (Ca, Sr, Ba) and Me 23+ WO43 (Al, Sc, In) according to the data acquired by the tubandt method, Russian Journal of Electrochemistry, 49, no. 9, 895–907, (2013).
 AA. Evdokimov and VA. Efremov, Trunov VK: Compounds of rare earth elements. Molybdates, tungstates. ?oscow, Nauka, ?oscow, 1991.
 MA. Poraj-Koshice, Atovmyan LO: Crystal chemistry and stereochemistry of coordination compounds of molybdenum, Nauka, Moscow, 1974.
 N. N. Pestereva, I. G. Safonova, S. S. Nokhrin, and A. Y. Neiman, Effect of MWO4 (M = Ca, Sr, Ba) dispersion on the interfacial processes in (+/-)WO3|MWO4|WO3(-/+) cells and transport properties of metacomposite phases, Russian Journal of Inorganic Chemistry, 55, no. 6, 876–882, (2010).
 LF. Grigorieva, Diagrams of refractory oxide systems, Nauka, Leningrad, 1988.
 RD. Shannon and A. Acta Crystallogr. Sect, (1976)., 751.