Phase Equilibria and Crystal Chemistry of the CaO-¿Sm2O3-CoOz System at 885 °C in Air

Published: June 27, 2015


Winnie K. Wong-Ng, William J. Laws, Saul H. Lapidus, James A. Kaduk


The CaO-¿Sm2O3-CoOz system prepared at 885 °C in air consists of two calcium cobaltate compounds, namely, the 2D thermoelectric oxide solid solution, (Ca3-xSmx)Co4O9-z (0 x 0.5) which has a misfit layered structure, and the 1D Ca3Co2O6 which consists of chains of alternating CoO6 trigonal prisms and CoO6 octahedra. Ca3Co2O6 was found to be a point compound without the substitution of Sm on the Ca site. A solid solution region of distorted perovskite, (Sm1-xCax)CoO3-z (0x0.22, space group Pnma) was established. The reported Sm2CoO4 phase was not observed at 885 °C, but a ternary Ca-doped oxide, (Sm1+xCa1-x)CoO4-z (I4/mmm) where 0
Citation: Solid State Sciences
Volume: 48
Pub Type: Journals


Phase diagram of CaO-¿Sm2O3-CoOz, thermoelectric oxide system, tie-line phase relationships, structure for (Sm1-xCax)2O3-z, and (Sm1+xCa1-x)CoO4-z
Created June 27, 2015, Updated November 10, 2018