Thallium ionic conductivity of new thallium indium hafnium molybdate ceramics
- PDF / 1,461,183 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 75 Downloads / 239 Views
ORIGINAL PAPER
Thallium ionic conductivity of new thallium indium hafnium molybdate ceramics Victoria G. Grossman 1 & Jibzema G. Bazarova 1 & Maksim S. Molokeev 2,3 & Bair G. Bazarov 1 Received: 11 June 2020 / Revised: 12 August 2020 / Accepted: 13 August 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract In the process of studying the system Tl2MoO4–In2(MoO4)3–Hf(MoO4)2, a new thallium indium hafnium molybdate was found. The crystal structure of the molybdate Tl5InHf(MoO4)6 was determined in the centrosymmetric space group R3c (a = 10.63893 (5) Å, c = 38.1447(3) Å; V = 3739.04 (4) Å3, Z = 6). The structure is a three-dimensional framework consisting of alternating (Hf,In)O6-octahedra connected by МоО4-tetrahedra. Each octahedron has common vertices with tetrahedra. The atoms arranged in this way form channels extended along with the a and b axes, in which thallium atoms are located. The conductivity behavior of Tl5InHf(MoO4)6 ceramics was studied in the temperature range from 300 to 870 K. The conductivity of the heavy cations of thallium is activated with increasing temperature. Keywords Synthesis . Thallium . Molybdates . Phase diagram . DSC . Conducting material
Introduction Currently, there is great interest in inorganic compounds (in particular, molybdenum-containing [1]) which exhibit the properties of catalysts [2–4], ferroelectric, piezoelectric, photoluminescent [5], laser [6, 7], and magnetic and have high ionic conductivity [8–18]. The molybdates are the proposed candidates for the creation of phosphors, white LEDs, and active lasers [19–25]. In recent decades, ternary molybdates with the general chemical formula AxByCz(MoO4)n, containing various combinations of A, B, and C cations, have been actively studied. For these compounds, the most characteristic structures are NASICON [26] and alluaudite [27]. Due to their structural features, they have high ionic conductivity (σ = 10 −3 – * Victoria G. Grossman [email protected] 1
Siberian Branch, Russian Academy of Sciences, Baikal Institute of Nature Management, Sakhyanovoy St., 6, Ulan-Ude 670047, Buryat Republic, Russia
2
Federal Research Center KSC, Siberian Branch, Russian Academy of Sciences, Kirensky Institute of Physics, 50 / 38 Akademgorodok, Krasnoyarsk 660036, Russia
3
Siberian Federal University, 82 Svobodniy Av., Krasnoyarsk 660041, Russia
10−2 S cm−1). For example, Na1–xA1–xR1 + x(MoO4)3 (A = Mg, Mn, Co, Ni, Zn, Cd; R = Al, Fe, Cr, Sc, In) and Ag1– xMg1–xR1 + x(MoO4)3 (where R = Al or Sc and 0 ≤ x ≤ 0.5) crystallize in the NASICON-type structure (space group R3 c) (sodium (Na) Super Ionic CONductor) [28–30]. A specific feature of phases with a NASICON structure is a rhombohedral framework {[R2(MoO4)]3n-}3∞ consisting of RO6 octahedra and MoO4 tetrahedra. A(R) atoms are at threefold axes and MoO4 groups are at twofold axes. The vacant parts of octahedral and tetrahedral voids merge into a three-dimensional network of channels, which are filled with alkali metal cations. This contributes to high ionic conductivity
Data Loading...
