87694 20200716101433.0 doi 10.1016/j.jssc.2019.02.014 sideral 110884 ART-2019-110884 eng Trussov, I.A. Understanding the complex structural features and phase changes in Na 2 Mg 2 (SO 4 ) 3 : A combined single crystal and variable temperature powder diffraction and Raman spectroscopy study 2019 Access copy available to the general public Unrestricted Sodium mixed metal sulphates have attracted considerable attention, both in terms of mineralogy and more recently due to interest in Na ion containing materials for battery applications. The phase, Na 2 Mg 2 (SO 4 ) 3 , has been previously reported to undergo a phase change to langbeinite at high temperatures, which is interesting given that usually the langbeinite structure is only adopted when large alkali metal ions, e.g. K, Cs, are present. Nevertheless the room temperature structure of this phase has remained elusive, and so in this work, we report a detailed structural study of this system. We show that room temperature Na 2 Mg 2 (SO 4 ) 3 can only be prepared by quenching from high temperature, with slow cooling leading to phase separation to give the previously unreported systems, Na 2 Mg(SO 4 ) 2 and Na 2 Mg 3 (SO 4 ) 4 . We report the structures of quenched Na 2 Mg 2 (SO 4 ) 3 (monoclinic, P2 1 ), as well as Na 2 Mg(SO 4 ) 2 (triclinic, P1¯) and Na 2 Mg 3 (SO 4 ) 4 (orthorhombic, Pbca), detailing their complex structural features. Furthermore, we report a study of the thermal evolution of quenched Na 2 Mg 2 (SO 4 ) 3 with temperature through variable temperature XRD and Raman studies, which shows a complex series of phase transitions, highlighting why this phase has proven so elusive to characterise previously, and illustrating the need for detailed characterisation of such sulphate systems. info:eu-repo/grantAgreement/ES/MINECO-FEDER/MAT2016-77769R info:eu-repo/semantics/openAccess by-nc-nd http://creativecommons.org/licenses/by-nc-nd/3.0/es/ 2.726 2019 0.559 2019 CHEMISTRY, INORGANIC & NUCLEAR 14 / 45 = 0.311 2019 Q2 T1 Ceramics and Composites 2019 Q2 CHEMISTRY, PHYSICAL 87 / 158 = 0.551 2019 Q3 T2 Condensed Matter Physics 2019 Q2 Physical and Theoretical Chemistry 2019 Q2 Inorganic Chemistry 2019 Q2 Materials Chemistry 2019 Q2 Electronic, Optical and Magnetic Materials 2019 Q2 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Male, L.L. (orcid)0000-0002-5793-2058 Sanjuan, M.L. Universidad de Zaragoza (orcid)0000-0001-8751-0983 Orera, A. Universidad de Zaragoza Slater, P.R. 2003 395 Universidad de Zaragoza Dpto. Física Materia Condensa. Área Física Materia Condensada 272 (2019), 157-165 J. solid state chem. JOURNAL OF SOLID STATE CHEMISTRY 0022-4596 2237258 http://zaguan.unizar.es/record/87694/files/texto_completo.pdf Postprint 269045 http://zaguan.unizar.es/record/87694/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:87694 articulos driver 2020-07-16-08:52:35 ARTICLE