Synthesis of Ba4Mn3O10 and Ba4Mn2TO10 (T = Pt, V)

Abstract

Materials with noncentrosymmetric crystal structure have applications in laser technology, access memory elements, energy-conversion, and spintronics.  Ba4Mn3O10 adopts an orthorhombic and centrosymmetric structure within space group Cmca (No.64).  Previous research has found that substitutions of one third of Mn atoms with a transition metal such as Ru and Ti, have resulted in the parent compound altering from a centrosymmetric to noncentrosymmetric phase.  Examination of Ruthenium and Titanium shows ionic radius sizes of 0.62Å and 0.605Å in the compound, respectively, which are much larger than that of Mn (0.53 Å). To determine if this radius size is a factor in the formation of derivative compounds in the Ba4Mn3O10 series, more ions of similar size were chosen to be substituted. Substitutions of Pt (0.625Å) and V (0.58Å) were attempted to form Ba4Mn2PtO10 and Ba4Mn2VO10. The synthesis of these samples was carried out through heating of stoichiometric quantities of the starting compounds BaCO3, MnO2, PtO2, and VO2.  The samples were heated to 1050°C in 12 hours and dwelled at the set temperature for 120 hours. The samples were then cooled to room temperature.  The purity of the samples was examined through powder X-ray diffraction (PXRD).  Different heating profiles were attempted to achieve phase pure samples, which have potential to show different magnetic properties compared to the parent compound.