STRUCTURE OF THE IRON - CHROME SPINELS
Abstract
X-ray diffraction intensity measurements and saturation magnetic moment measurements were made on several samples of the spinel system FeFeQ Cr O n , 0 ^ x ^ 2, cl X H* for the purpose of finding the details in the structure of this system which were unknown. From the X-ray measurements the oxygen parameter of each sample was deduced. These parameters indicated inverse spinels for low values of x, partially inverse spinels for intermediate values of x, and normal spinels for 1.3 ^ x ^ 2 . It was inferred from the magnetic measurements that the spins of all cations on A sites are antiparallel to the spins of all cations on B sites in spinels with low values of x, whereas for other spinels the spins of cations on the B sites are not all parallel. This made it impossible to determine the arrangement of cations on the A and B sites in a spinel from its measured value of magnetic moment, except in spinels with a low value of x. The magnetic measurements indicated that spinels are inverse in the region 0 e x e 0.3* PREV
Degree
Ph.D.
Subject Area
Physics
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