Microwave-Assisted Synthesis, Characterization, and Thermal Decomposition of Rare-Earth Metal Disulfides RES2 (RE = La, Pr, Nd)

作者：Bartsch Christian; Ahrens Eike; Doert Thomas^*

来源：Zeitschrift fur Anorganische und Allgemeine Chemie, 2012, 638(15): 2491-2497.

DOI：10.1002/zaac.201200221

• Polychalcogenides
• Rare-earth metals
• Microwave-assisted synthesis
• Nanostructures
• Thermal decomposition

Microwave-assisted metathesis reactions from anhydrous rare-earth metal trichlorides and alkali metal polychalcogenides in dimethylformamide in the temperature interval 160 degrees C = T = 220 degrees C yield sub-micron and nanometer scaled particles of the rare-earth metal disulfides RES2 (RE = La, Pr, Nd). The samples were characterized by X-ray powder diffraction, electron microscopy, chemical analysis, and Raman and UV/Vis spectroscopy. The products adopt the monoclinic a-RES2 type (space group P21/a) and form desert rose-like agglomerates. The nano-scaled samples show significantly reduced optical bandgaps compared to the bulk material. The thermal decomposition in air at 550 degrees C = T = 1000 degrees C yields rare-earth metal oxide sulfates RE2O2SO4.

• 出版日期2012-12