Crystal Structure of Solid Solutions in the Sm2O3–CaO–MO and Ln2O3–SrO–MO Systems (Ln = Sm, Gd; M = Fe, Co)

Abstract

Complex oxides in the Sm₂O₃–CaO–MO and Ln₂O₃–SrO–MO systems (Ln = Sm, Gd; M = Fe, Co) were prepared via the glycerol-nitrate technique at 1100°С in air. The homogeneity ranges for the solid solutions were determined as follows: Sr_1 – хGd_хCoO_{3 – δ} (0.1 ≤ х ≤ 0.4); Sr_2 – yGd_yCoO_4 – δ (0.8 ≤ y ≤ 1.2); Sr_1 – хGd_хFeO_3 – δ (0.05 ≤ х ≤ 0.30 and 0.80 ≤ х ≤ 1.0); Ca_1 – xSm_xFeO_3 – δ (0.70 ≤ x ≤ 1.0); Sr_2 – ySm_yFeO_4 – δ (0.7 ≤ y ≤ 0.8); Sr_2 – yGd_yFeO_4 – δ (0.75 ≤ y ≤ 0.8); Ca_2 – уSm_уFeO_4 – δ (у = 0.90); Sr_3 – zSm_zFe₂O_7 – δ (0 ≤ z ≤ 0.3 and z = 1.8); and Sr_3 – zGd_zFe₂O_{7 – δ} (0 ≤ z ≤ 0.3 and z = 1.9). For all single phase oxides, the crystal structure was determined and the unit cell parameters, the unit cell volume, and the structural parameters were refined.