ISSN:
1551-2916
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Annealing studies were conducted on bulk La0.7Ca0.3MnO3−δ to determine the sensitivity of its structural and magnetic properties to oxygenation conditions. Standard bulk sintering conditions, thin-film annealing conditions for obtaining good magnetoresistive properties, and a reducing anneal, which corresponded to the onset of phase decomposition, were conducted. The main phase formed was a face-centered (fcc) pseudocubic double-perovskite structure, with cell parameters of a∼ 2ap∼ 0.772 nm, where ap is the single-perovskite cubic cell parameter. A minor superstructure—body-centered pseudotetragonal, with lattice parameters of c= 4ap and a=√2ap—was observed in samples with (3 −δ) 〈 3. A maximum of 20% of the superstructure was formed using the most-reducing conditions. The superstructure had a lower critical temperature than the main phase and depressed ferromagnetic order.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1151-2916.2001.tb00736.x
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