Phase identification and structure determination from multiphasic crystalline powder samples by rotation electron diffraction
(English)In: Journal of applied crystallography, ISSN 0021-8898, E-ISSN 1600-5767Article in journal (Refereed) Accepted
Phase identification and structure characterisation are important in synthetic and material science. It is difficult to characterise the individual phases from multiphasic crystalline powder samples, especially if some of the phases are unknown. Here we describe how this problem can be solved by combining rotation electron diffraction (RED) and powder X-ray diffraction (PXRD). Four phases were identified on the same transmission electron microscopy (TEM) grid from a multiphasic sample in the Ni-Se-O-Cl system and their structures were solved from the RED data. Phase 1 (NiSeO3) was found in the Inorganic Crystal Structure Data (ICSD) database using the information from RED. Phase 2 (Ni3Se4O10Cl2) is an unknown compound but it is iso-structural to Co3Se4O10Cl2, which was recently solved by single crystal X-ray diffraction. Phase 3 (Ni5Se6O16Cl4H2) and Phase 4 (Ni5Se4O12Cl2) are new compounds. The fact that there are at least four different compounds in the as-synthesised material explains why the phase identification and structure determination could not be done only by PXRD. The RED method makes phase identification from such multiphasic powder samples much easier compared to powder X-ray diffraction. The RED method also makes structure determination of submicron-sized crystals from multiphasic samples possible.
IdentifiersURN: urn:nbn:se:su:diva-108925OAI: oai:DiVA.org:su-108925DiVA: diva2:761513