The ternary system Sm 2O 3–SrO–CuO: compounds and phase relations

Abstract

The subsolidus phase relations of the Sm 2O 3–SrO–CuO ternary system have been investigated by X-ray powder diffraction. All samples were synthesized in air at 950–1000°C. The system can be divided into ten three-phase regions and two solid solutions. In this system, there exist one binary solid solution Sr 14− x Sm x Cu 24O y , one ternary solid solution Sm 1+ x Sr 2− x Cu 2O y and one ternary compound SmSr 3Cu 2O y . The solid solution Sr 14− x Sm x Cu 24O y (0⩽ x⩽6.5) crystallizes in an orthorhombic unit cell with space group Fmmm and lattice constants of a=3.950(1)–3.975(1) Å, b=11.475(1)–11.311(3) Å and c=13.401(2)–12.858(4) Å. The solid solution Sm 1+ x Sr 2− x Cu 2O y (0⩽ x⩽0.25) belongs to an orthorhombic system with space group Immm, cell parameters a=3.772(1)–3.774(3) Å, b=11.606(2)–11.226(6) Å and c=20.053(3)–20.086(3) Å. The ternary compound SmSr 3Cu 2O y crystallizes in an orthorhombic unit cell with space group Immm and lattice constants of a=3.7123(4) Å, b=3.7875(3) Å and c=12.6395(9) Å.