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

• Main Authors: O.I. Zaremba, N.O. Filipenko, A.M. Horin, R.E. Gladyshevskii
• Format: Article
• Language: English
• Published: Publishing House "Akademperiodyka" 2019-08-01
• Series: Доповiдi Нацiональної академiї наук України
• Subjects: crystal structure; magnetic properties; manganates; perovskites; phase equilibria
• Online Access: http://www.dopovidi-nanu.org.ua/en/archive/2019/8/9

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.