Ba5Fe4NiO13.5 (BaFe0.8Ni0.2O2.70) was synthesized by heating the mixed nitrates at 700°C for 72 h in air. The crystal structure has been analyzed by Rietveld analysis of the powder X-ray diffraction data. Ba5Fe4NiO13.5 has a hexagonal unit cell, space group P63/mmc with lattice parameters a = 5.7713(3) Å and c = 24.5812(16) Å. The structure is formed by the stacking of 10 close-packed BaO3 layers consisting of six hexagonal and four cubic sequences. This stacking creates trinuclear and binuclear face sharing octahedral units that are linked by corner sharing into a column approximately 24-Å high. The Ni ion preferentially occupies the central octahedral interstice of the trinuclear unit and the Fe ions occupy all the other sites. The interatomic distances and the result of a magnetic measurement are consistent with the presence of 50% high-spin Fe4+ 50% high-spin Fe3+, and low-spin Ni3+ states.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry