A comprehensive variable temperature study of the layered oxide, Ca2Mn3O8

[摘要] Ca2Mn3O8 forms a delafossite-related layered structure, which crystallises with monoclinic C-2/m sym-metry. 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 similar to 400-700 K with an activation energy of 0.50 +/- 0.01 eV. (C) 2020 Elsevier B.V. All rights reserved.

[发布日期] 2020-11-30

[关键词] Layered oxides;Neutron diffraction;Electronic measurements