ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The ultrafine spinel NiFe〈sub〉1.9〈/sub〉M〈sub〉0.1〈/sub〉O〈sub〉4〈/sub〉 powders (M=Al, Y, Cr, Fe) were synthesized by thermal decomposition of appropriate mixtures of complex compounds with acetylacetone - (2,4 pentadione) ligands ([M(AA)〈sub〉x〈/sub〉]) at 500 °C.Samples were annealed in the temperature range 600-1000 °C and the crystallization process was followed by XRD. The largest crystallite size and the highest crystallization rate are observed for NiFe〈sub〉1.9〈/sub〉Al〈sub〉0.1〈/sub〉O〈sub〉4〈/sub〉, while the opposite was found for NiFe〈sub〉1.9〈/sub〉Y〈sub〉0.1〈/sub〉O〈sub〉4〈/sub〉. Strain value in NiFe〈sub〉1.9〈/sub〉Y〈sub〉0.1〈/sub〉O〈sub〉4〈/sub〉 changes sign at temperatures between 700-800 °C, while for NiFe〈sub〉1.9〈/sub〉M〈sub〉0.1〈/sub〉O〈sub〉4〈/sub〉 (M=Al, Cr) it has apositive sign and reaches the maximum value at 700 °C.The crystal structure of the samples annealed at 1000 °C was refined using the Rietveld profile method. Cation substitution in Ni-ferrite changes its structural and microstructural parameters, and can also significantly influence other physical properties
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/07/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.443-444.283.pdf
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