Synthesis and properties of a new quadruple perovskite: A-site ordered PbMn{sub 3}Mn{sub 4}O{sub 12}

• Published in: Journal of solid state chemistry 2012-06, Vol.190
• Main Authors: Locherer, T., Dinnebier, R., Kremer, R.K., Greenblatt, M., Jansen, M.
• Format: Article
• Language: English
• Subjects: AMBIENT TEMPERATURE; ANTIFERROMAGNETISM; CALORIMETRY; FERROELECTRIC MATERIALS; FREQUENCY DEPENDENCE; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; MAGNETIC FIELDS; MAGNETIC SUSCEPTIBILITY; MATERIALS SCIENCE; PERMITTIVITY; PEROVSKITE; POWDERS; SPACE GROUPS; SYNTHESIS; TEMPERATURE DEPENDENCE; TRIGONAL LATTICES; X-RAY DIFFRACTION
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/J.JSSC.2012.02.036

PbMn{sub 3}Mn{sub 4}O{sub 12} a quadruple perovskite was prepared by high pressure and high temperature synthesis. Powder X-ray diffraction (PXD) and differential scanning calorimetry reveal a structural phase transition at {approx}380 K. Rietveld refinement of the synchrotron room temperature data indicate rhombohedral symmetry (R-3) with a=6.43675(4) A and {alpha}=109.556(2) Degree-Sign . Similar 423 K PXD data refined in a body centered cubic cell (Im-3) with a=7.4283(9) A. The temperature variation of magnetization, shows a magnetic field dependent antiferromagnetic-like transition at 68 K, and dynamic fluctuations indicative of magnetic frustration. The semiconducting electrical behavior indicates a large decrease in the conductivity near 68 K. The temperature dependence of the real part of the dielectric constant, {epsilon}{sub real} increases dramatically at {approx}68 K, and shows relaxor-type ferroelectric behavior as a function of frequency. The intimate coupling of magnetic, electrical and dielectric properties at 68 K in PbMn{sub 3}Mn{sub 4}O{sub 12} suggests possible multiferroic behavior. - Graphical abstract: Resistance vs. temperature plot showing drastically increasing resistances at temperatures below 68 K (a). Formation of a frequency dependency of the dielectric constant between 68 K and ambient temperature (b). Sharp cusp in the magnetic susceptibility observed at 68 K which is suppressed with increasing magnetic field (c) indicates coupling of magnetic, electric and dielectric effects. Highlights: Black-Right-Pointing-Pointer PbMn{sub 3}Mn{sub 4}O{sub 12} a quadruple perovskite was prepared at high pressure. Black-Right-Pointing-Pointer A structural transition is seen at 380 K from space group R-3-to-Im-3. Black-Right-Pointing-Pointer An antiferromagnetic transition is observed at 68 K. Black-Right-Pointing-Pointer It is semiconducting with a large decrease in the conductivity near 68 K. Black-Right-Pointing-Pointer The temperature dependence of the dielectric constant increases dramatically at 68 K. Black-Right-Pointing-Pointer Coupling of magnetic, electric and dielectric behavior suggests multiferroicity.