Phases with perovskite structure in the A-R-Mn-O systems, where A - alkali-earth metal, R - rare-earth metal

Zaremba, IO
Filipenko, NO
Horin, AI
1Gladyshevskii, RE
1Ivan Franko National University of Lviv
Dopov. Nac. akad. nauk Ukr. 2019, 8:69-77
Section: Chemistry
Language: Ukrainian

The interaction of the components in the A—R—Mn—O systems is studied by Xray diffraction on polycrystalline samples synthesized by solidstate reaction at 1000 °C. In the Ba—R—Mn—O systems, where R = Pr, Nd, or Sm, the existence of the Ba0.5Pr0.5MnO3, Ba0.5Nd0.5MnO3, and Ba0.5Sm0.5MnO3 compounds with cubic CaTiO3-type structure is confirmed, whereas, for R = Ce, Eu, Gd, and the heavy rareearth metals, quaternary perovskites were not formed under the conditions of our synthesis. The existence of Sr0.35Gd0.65MnO3 and Ca0.5Gd0.5MnO3 with orthorhombic GdFeO3type structure is confirmed in the {Sr,Ca}—Gd—Mn—O systems. The isothermal crosssections of the SrO—Gd2O3—Mn2O3 and CaO—Gd2O3—Mn2O3 systems at 1000 °С are constructed. The temperature dependence of the magnetic susceptibility, c vs. T, is studied for Sr0.35Gd0.65MnO3. Such type of dependence is described by the Curie—Weiss law and is typical of paramagnets. The experimental value of the effective magnetic moment is equal 10.98 μB.

Keywords: crystal structure, magnetic properties, manganates, perovskites, phase equilibria, solidstate reaction

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