Ioana Jitaru

Lanthanum chromites doped with divalent transition metals

Abstract Heteropolynuclear complex compounds isolated in Cr 2 O 3 · x H 2 O–La(NO 3 ) 3 –M(NO 3 ) 2 –A–NH 3 , (A=CH 3 COO − ,C 2 O 4 2− ; M=Cu, Ni) systems were used as precursors for LaCr 1− x M x O 3 . The perovskite structure of doped lanthanum chromites was determined by XRD analysis. The unit cell volumes, specific surface areas and magnetic properties were investigated. The proposed methods offer new, simple, less expensive procedures for obtaining doped lanthanum chromites.

Complex Precursors for Doped Lanthanum Chromite Synthesis

Doped lanthanum chromites are investigated as ceramic interconnect materials to be used in high-temperature solid oxide fuel cells (SOFCs). This paper deals with the preparation of LaCr1−xMxO3 (M = Ni, Cu, x = 0 − 0.2) from complex precursors isolated in the La(NO3)3-Cr(NO3)3-M(NO3)2-urea system. The isolated complex precursors were characterized by atomic absorption spectrometry, electronic, and FT-IR spectra, as well as, by thermal analysis. Doped lanthanum chromites, LaCr1−xMxO3 (M = Ni, Cu) were prepared by calcining of corresponding urea-based precursors at 1000-1200°C for 2 h. Doped mixed-oxide samples were characterized by X-ray diffraction (XRD), Scanning electron-microscopy-energy-dispersive X-ray analysis (SEM-EDX), electrical conductivity, as well as magnetic measurements.