Cation distribution and magnetic properties in chromium-substituted nickel ferrites prepared using aerosol route
✍ Scribed by Sonal Singhal; Kailash Chandra
- Publisher
- Elsevier Science
- Year
- 2007
- Tongue
- English
- Weight
- 399 KB
- Volume
- 180
- Category
- Article
- ISSN
- 0022-4596
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✦ Synopsis
Cation distribution have been investigated using X-ray diffraction, magnetic and Mo¨ssbauer spectral studies in chromium-substituted nickel ferrites prepared by aerosol route. Cation distribution indicates that the chromium atom occupy octahedral site upto x ¼ 0.8, and then also enters into tetrahedral site. The saturation magnetization decreases linearly with the increase of chromium concentration due to the diamagnetic nature of the Cr 3+ . However, interesting behaviour is observed in the coercivity. Initially it increases slowly with the chromium concentration but when x40.8 a very large increase has been observed. This was attributed to the specific cation distribution of Cr 3+ which results an unquenched orbital angular momentum and a large anisotropy. Room temperature Mo¨ssbauer spectra of as obtained samples exhibited a broad doublet resolved into two doublets corresponding to the surface and internal region atoms. The samples annealed at 1200 1C show broad sextets, which were fitted with different sextets, indicating different local environment of both tetrahedral and octahedral coordinated iron cation.