Zinc ferrites (ZnFe2O4) prepared in the micron regime is purported to be a normal spinel with no net magnetization. Recent investigations carried out by various researchers clearly shows that, contrary to the earlier belief, it is not a normal spinel, and exhibits a net magnetization when they are prepared in the form of fine particles. This is possible only if Zn2+ occupies octahedral sites (B), which results in a magnetic interaction. Various hypotheses exists and if this is to tested, a systematic study on similar compounds is to be undertaken.
It is known from the literature that the cations like Cd, Zn, and Mn have a strong tetrahedral site (A) preference. Compounds containing Zn and Cd normally results in a normal spinel. Other compounds exhibiting normal spinel structure are ZnAl2O4 and CdAl2O4.In my work my aim is to synthesize fine particles of ZnFe2O4 ,CdFe2O4, MnFe2O4, ZnAl2O4, CdAl2O4, and MnAl2O4. Magnetic, electric and structural properties of the above mentioned ferrites and aluminates will be evaluated to determine the cation distribution. The occupation of Zn/Cd/Mn on tetrahedral (A) and octahedral (B) site with respect to particle size will be determined. For comparison all the above-mentioned compounds will be prepared by two different routes namely, High temperature methods (ceramic technique) and wet chemicals methods (co precipitation low temperature technique). Data on structural, magnetic, and electrical properties will be generated and a possible relationship between the occupation of these ions on A or B sites with particle size will be established. Furthermore with the data generated using these techniques a plausible mechanism / and an explanation for the anomalous behaviour of ‘normal’ spinels will be arrived at. As far as the magnetic spinels are concerned the variation of Ms,Hc with particle size will also be investigated. Neutron scattering experiments will be employed to evaluate magnetic structure of these spinels.
It is known from the literature that the cations like Cd, Zn, and Mn have a strong tetrahedral site (A) preference. Compounds containing Zn and Cd normally results in a normal spinel. Other compounds exhibiting normal spinel structure are ZnAl2O4 and CdAl2O4.In my work my aim is to synthesize fine particles of ZnFe2O4 ,CdFe2O4, MnFe2O4, ZnAl2O4, CdAl2O4, and MnAl2O4. Magnetic, electric and structural properties of the above mentioned ferrites and aluminates will be evaluated to determine the cation distribution. The occupation of Zn/Cd/Mn on tetrahedral (A) and octahedral (B) site with respect to particle size will be determined. For comparison all the above-mentioned compounds will be prepared by two different routes namely, High temperature methods (ceramic technique) and wet chemicals methods (co precipitation low temperature technique). Data on structural, magnetic, and electrical properties will be generated and a possible relationship between the occupation of these ions on A or B sites with particle size will be established. Furthermore with the data generated using these techniques a plausible mechanism / and an explanation for the anomalous behaviour of ‘normal’ spinels will be arrived at. As far as the magnetic spinels are concerned the variation of Ms,Hc with particle size will also be investigated. Neutron scattering experiments will be employed to evaluate magnetic structure of these spinels.
2 comments:
"The oxygen deficiency produced by the high energy ball milling" - pooja do you have any journal reference for this. do you differentiate between oxygen deficiency and oxygen vacancy.
Can ball milling result in oxygen deficient samples?
"The oxygen deficiency produced by the high energy ball milling" - pooja do you have any journal reference for this. do you differentiate between oxygen deficiency and oxygen vacancy.
Can ball milling result in oxygen deficient samples?
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