000087694 001__ 87694 000087694 005__ 20200716101433.0 000087694 0247_ $$2doi$$a10.1016/j.jssc.2019.02.014 000087694 0248_ $$2sideral$$a110884 000087694 037__ $$aART-2019-110884 000087694 041__ $$aeng 000087694 100__ $$aTrussov, I.A. 000087694 245__ $$aUnderstanding 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 000087694 260__ $$c2019 000087694 5060_ $$aAccess copy available to the general public$$fUnrestricted 000087694 5203_ $$aSodium 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. 000087694 536__ $$9info:eu-repo/grantAgreement/ES/MINECO-FEDER/MAT2016-77769R 000087694 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc-nd$$uhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/ 000087694 590__ $$a2.726$$b2019 000087694 592__ $$a0.559$$b2019 000087694 591__ $$aCHEMISTRY, INORGANIC & NUCLEAR$$b14 / 45 = 0.311$$c2019$$dQ2$$eT1 000087694 593__ $$aCeramics and Composites$$c2019$$dQ2 000087694 591__ $$aCHEMISTRY, PHYSICAL$$b87 / 158 = 0.551$$c2019$$dQ3$$eT2 000087694 593__ $$aCondensed Matter Physics$$c2019$$dQ2 000087694 593__ $$aPhysical and Theoretical Chemistry$$c2019$$dQ2 000087694 593__ $$aInorganic Chemistry$$c2019$$dQ2 000087694 593__ $$aMaterials Chemistry$$c2019$$dQ2 000087694 593__ $$aElectronic, Optical and Magnetic Materials$$c2019$$dQ2 000087694 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/acceptedVersion 000087694 700__ $$aMale, L.L. 000087694 700__ $$0(orcid)0000-0002-5793-2058$$aSanjuan, M.L.$$uUniversidad de Zaragoza 000087694 700__ $$0(orcid)0000-0001-8751-0983$$aOrera, A.$$uUniversidad de Zaragoza 000087694 700__ $$aSlater, P.R. 000087694 7102_ $$12003$$2395$$aUniversidad de Zaragoza$$bDpto. Física Materia Condensa.$$cÁrea Física Materia Condensada 000087694 773__ $$g272 (2019), 157-165$$pJ. solid state chem.$$tJOURNAL OF SOLID STATE CHEMISTRY$$x0022-4596 000087694 8564_ $$s2237258$$uhttps://zaguan.unizar.es/record/87694/files/texto_completo.pdf$$yPostprint 000087694 8564_ $$s269045$$uhttps://zaguan.unizar.es/record/87694/files/texto_completo.jpg?subformat=icon$$xicon$$yPostprint 000087694 909CO $$ooai:zaguan.unizar.es:87694$$particulos$$pdriver 000087694 951__ $$a2020-07-16-08:52:35 000087694 980__ $$aARTICLE