Synthesis, Structural, Thermal, and Electronic Properties of Palmierite-Related Double Molybdate α‑Cs2Pb(MoO4)2

• Published in: Inorganic chemistry 2017-03, Vol.56 (6), p.3276-3286
• Main Authors: Solodovnikov, Sergey F, Atuchin, Victor V, Solodovnikova, Zoya A, Khyzhun, Oleg Y, Danylenko, Mykola I, Pishchur, Denis P, Plyusnin, Pavel E, Pugachev, Alexey M, Gavrilova, Tatiana A, Yelisseyev, Alexander P, Reshak, Ali H, Alahmed, Zeyad A, Habubi, Nadir F
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.6b02653

Cs2Pb­(MoO4)2 crystals were prepared by crystallization from their own melt, and the crystal structure has been studied in detail. At 296 K, the molybdate crystallizes in the low-temperature α-form and has a monoclinic palmierite-related superstructure (space group C2/m, a = 2.13755(13) nm, b = 1.23123(8) nm, c = 1.68024(10) nm, β = 115.037(2)°, Z = 16) possessing the largest unit cell volume, 4.0066(4) nm3, among lead-containing palmierites. The compound undergoes a distortive phase transition at 635 K and incongruently melts at 943 K. The electronic structure of α-Cs2Pb­(MoO4)2 was explored by using X-ray emission spectroscopy (XES) and X-ray photoelectron spectroscopy methods. For α-Cs2Pb­(MoO4)2, the photoelectron core-level and valence-band spectra and the XES band representing the energy distribution of Mo 4d and O 2p states were recorded. Our results allow one to conclude that the Mo 4d and O 2p states contribute mainly to the central part and at the top of the valence band, respectively, with also significant contributions throughout the whole valence-band region of the molybdate under consideration.