The crystal structure of CaLaMnFeO6 double perovskite

A single-phase, polycrystalline sample of the double perovskite CaLaMnFeO6 was prepared by solid-state synthesis and characterized with neutron powder diffraction. The compound belongs to the class of AA′BB′O6 perovskites with a random distribution of Mn and Fe atoms over the B-cation sub-lattice. Rietveld refinement of the room temperature neutron powder diffraction data revealed that the crystal structure of CaLaMnFeO6 is disordered with orthorhombic symmetry (space group Pbnm) having lattice parameters a = 5.4468(5) Å, b = 5.4386(5) Å, c = 7.6862(5) Å. The crystal structure is distorted due to the small size of the La+3 and Ca+2 cations, which force the (Mn/Fe)O6 octahedra to tilt in order to optimize the 12-coordinated (La/Ca)–O bond distances.