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

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 a-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) run, beta = 115.037(2)degrees, Z = 16) possessing the largest unit cell volume, 4.0066(4) nm(3), among lead-containing palmierites. The compound undergoes a distortive phase transition at 635 K and incongruently melts at 943 K. The electronic structure of alpha-Cs2Pb(MoO4)(2) was explored by using X-ray emission spectroscopy (XES) and X-ray photoelectron spectroscopy methods. For alpha-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 0 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.