On the Crystal Chemistry and Stability of Sm2+ in SmSO4 and Solid Solutions of M1−xSmxSO4 (M=Ba, Sr)

• Published in: Journal of solid state chemistry Vol. 154; no. 2; pp. 535 - 541
• Main Authors: Mikhail, P., Sieber, A., Samtleben, T., Trusch, B., Lüthi, T., Hulliger, J.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01-11-2000; Elsevier
• Subjects: Chemistry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; electrochemical synthesis; Elements and non-metal compounds (oxides, hydroxides, hydrides, sulfides, carbides, ...); Exact sciences and technology; flux growth; Inorganic chemistry and origins of life; Inorganic compounds; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other solid inorganic materials; Photoluminescence; Physics; Preparations and properties; Salts; Sm2; solid solution; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; sulfate; Sm2; sulfate; solid solution; electrochemical synthesis; flux growth; Fluorescence spectrum; Strontium sulfate; Flux growth; Chemical precipitation; Thermal decomposition; Crystal chemistry; High temperature; Experimental study; Lattice parameters; Solid solution; Controlled atmosphere; X ray diffraction; Thermal stability; Inorganic compound; Barium sulfate; Lanthanide compound; Characterization; Lifetime; Chemical preparation; Chemical composition; Electrochemical reaction; Growth from solution; Samarium sulfates
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1006/jssc.2000.8876

Solid solution formation of Sm2+ and MSO4 (M=Sr, Ba) was investigated for syntheses using (i) a LiCl high-temperature solution exposed to a reducing atmosphere and (ii) precipitation reactions at room temperature starting from aqueous solutions of SmI2 or electrochemically gained Sm2+. In contrast to (ii), present results show that a high-temperature approach (i) yielded only a very low amount of Sm2+ in M1−xSmxSO4. Formation of a solid solution system (0<x<1) was confirmed for Sr1−xSmxSO4 and Ba1−xSmxSO4 by X-ray powder diffraction analysis and optical lifetime measurements. The unit cell parameters of Ba1−xSmxSO4 showed a slight deviation from Vegard's law. Positive and negative deviations are in agreement with results on solid solutions of Ba1−xSrxSO4. Compounds obtained by syntheses at room temperature were exposed to annealing at 450 to 850°C using a reducing or oxidizing atmosphere. In this temperature range, M1−xSmxSO4 (M=Sr, Ba) decomposed into Sm2O2(SO4) and the corresponding MSO4. Solid solutions of M1−xSmxSO4 (M=Ba, Sr) represent a new system for investigating Sm2+ in an oxide environment. There are only a few other oxide host lattices stabilizing divalent samarium.