A comprehensive variable temperature study of the layered oxide, Ca2Mn3O8
Abstract
Ca2Mn3O8 forms a delafossite-related layered structure, which crystallises with monoclinic C2/m symmetry. Compared with the delafossite-structure, the MnO6 layers in Ca2Mn3O8 exhibit an ordered cation void which forms a magnetic ‘bow-tie’ like connectivity of Mn4+ ion layers separated by Ca2+ ions. In-situ variable temperature diffraction data demonstrates that the structure is robust up to a temperature of approximately 1173 K before the material decomposes into the perovskite, CaMnO3 and marokite, CaMn2O4 phases. Simultaneous thermal analysis suggests that a very small amount of water remains within the layers post synthesis. Impedance spectroscopy indicates that Ca2Mn3O8 is an electronic conductor in the range ∼400–700 K with an activation energy of 0.50 ± 0.01 eV.
Citation
Stimpson , L , McNulty , J A , Morrison , F D , Mahjan , A , McCabe , E , Gibbs , A , Stenning , G , Jura , M & Arnold , D 2020 , ' A comprehensive variable temperature study of the layered oxide, Ca 2 Mn 3 O 8 ' , Journal of Alloys and Compounds , vol. 843 , 155633 . https://doi.org/10.1016/j.jallcom.2020.155633
Publication
Journal of Alloys and Compounds
Status
Peer reviewed
ISSN
0925-8388Type
Journal article
Description
The authors acknowledge the ISIS Neutron and Muon User Source for access to beamtime on HRPD (RB1520166 and RB1720182) [39,40]. We are also thankful for access to the instrumentation in the ISIS Materials Characterisation laboratory. We are grateful to Professor Mike Reece at Queen Mary University London for access to the spark plasma sintering (SPS) instrumentation and for assistance preparing pellets. LJV and JAM are grateful for the award of EPSRC DTA studentships.Collections
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