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A STUDY OF NANOCOMPOSITE WITH NICKEL OXIDE IN TWO AND SIX LINES FERRIHYDRITE

ABSTRACT

The role of particle magnetic moment distribution on magnetization of magnetic nanoparticles is used in analysis of magnetization data on a composite of nickel oxide and two lines ferrihydrite nanoparticles in super paramagnetic region. The presented analysis is found to be very helpful in estimating concentration of individual component in a magnetic nanocomposite. Magnetic particles require energy to overcome the energy barrier. This energy can be supplied in form of thermal energy by varying temperature or magnetic energy by varying strength of applied magnetic field. Rate of magnetization relaxation is affected by both temperature and applied magnetic field strength. Magnetization of magnetic nanoparticle systems is also affected by any history. The magnetization relaxation in any system can be nicely studied by measuring magnetization as a function of time at low temperature where the relaxation time is sufficiently large and can be measured easily. But in superparamagnetic state the relaxation time is very small ( 10−11 s) and so system achieves equilibrium easily at any temperature and applied magnetic field. In last several decades superparamagnetic behavior of ferro and ferrimagnetic nanoparticles were studied extensively. Researchers showed their interest in these systems mainly because of unique behavior exhibited by them. These systems also have many useful technological applications, as already discussed. But magnetic behavior of antiferromagnetic nanoparticles attracted the attention of scientists mainly in recent decades only.

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