ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The reduction of LnCoO3(Ln = La-Eu) in a hydrogen atmosphere of 2×106 Pa at 25 to 600° C was investigated by X-ray diffraction and thermogravimetric analysis, which were carried out to pursuein situ the reaction of reduction of LnCoO3. The amount of lattice oxygen consumed at 600° C increases on going from LaCoO3 to EuCoO3. It was shown that the reduction process proceeded through the formation of a series of oxygen-deficient structures in keeping the perovskite structures; for example, the final X-ray powder diffraction pattern of NdCoO3−x (x=1.1) could be indexed on a cubic cell (a = 0.39 nm) and an orthorhombic cell (a0=0.522 nm,b 0 = 0.559nm, c0 = 0.795nm), the relationship with the cubic cell beinga 0 ≃ 21/2 a c,b 0 ≃ 21/2 a c,c ≃ 2ac.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01114746
Permalink