Springer Online Journal Archives 1860-2000
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Abstract Decomposition products of δ-FeO(OH)-type Fe1−x M x O1−x (OH)1+x phases (M=Mg, Zn, Ca, Cd) have been studied by X-ray diffraction, electron diffraction and high-resolution transmission electron microscopy. It has been shown that the M=Mg and Cd δ-phases decompose to α-Fe2O3-based solid solutions which in turn undergo exsolution to form some MgO and CdO at a higher temperature. In the case of Fe1−x Zn x O1−x (OH)1+x , the decomposition proceeds over α-Fe2O3 ss to an unstable spinel solid solution. All decomposition products are topotactically related to their precursors in the decomposition chain. In the electron microscope some δ-type phases undergo in situ decomposition under intense beam bombardment with somewhat different results than obtained for thermal decomposition products under ambient conditions. The plate-like morphology and crystal size is retained in the decomposition products; however, the products have a more pitted appearance after decomposition.
Type of Medium: