Crystallite size dependence on the magnetic properties of nanocrystalline magnetite powders
- 作者：Bhattacharya ; A.K. ; Hartridge ; A. ; Majumdar ; C.K. ; Sengupta ; M. ; Das ; D. ; Chintalapudi ; S.N.
- 关键词：Nanocrystals ; Mö ; ssbauer spectroscopy ; X-ray diffraction
- 刊名：Journal of Magnetism and Magnetic Materials
- 出版年：1997
- 期刊代码：31_03048853
- 类别：ph
- 出版时间：December 11, 1997
- 卷：176
- 期：2-3
- 页码：l89-l92
- 文件大小：257 K
摘要
Single phase magnetite powders with crystallite sizes ranging from 8-50 nm were synthesised and studied using X-ray diffraction and Mössbauer spectroscopy. Lattice parameters were seen to decrease at very small crystallite sizes. Quadrupole splitting of the B sites increased with decreasing crystallite size before the spectrum collapsed into a doublet at the smallest sizes. These observations have been explained in terms of high surface-to-volume ratios in the small nanocrystals creating excessive lattice strain and large electric field gradients.