Abstract:
Now days, the studies of Nano particles of magnetic oxides have receive much attention because
of their promising technological advantages for application in medicine, sensors, magnetic
recordings, catalysts. Among wide range of ferrites nano particles Cobalt ferrite has attracted
much attention as a hard magnetic material exhibiting a high coercivity. It also shows an
enhanced saturation magnetization of about 80emu/g at room temperature and sizeable magneto
crystalline anisotropy. A temperature dependent model is necessary in order to understand the
behavior of magnetization process in ferromagnetic material at different temperatures. In the
present study a physical model based on Jiles-Atherton (JA) theory was developed to study the
effects of temperature on magnetic hysteresis Cobalt ferrite .This Thermal effects were
incorporated through temperature dependent hysteresis parameters of the existing model, adding
critical exponent and Curie temperature as additional parameters. The temperature dependent
Jiles- Atherton (JA) model was validated against measurements On Cobalt ferrite and the result
shows good agreement between theory and analytical method. The value of constant parameters
in the temperature dependent of magnetization of measured data of cobalt ferrite with curie point
of (Tc=793) starting from temperature ranges of 100k; and the critical exponent (𝛽1) was
estimated to be 0.4from fitting the analytical model of spontaneous magnetization to be measured
data while (𝛽2) and (𝛽3) are assumed to be (𝛽1/2) in pinning factor and domain density while
;they have same value with spontaneous magnetization in domain coupling and and reversibility
factor. The relation between them is spontaneous magnetization, pinning factor, domain density,
domain coupling are decreasing with temperature while reversibility factor increasing with
temperature.
Key words: Cobalt ferrite, magnetization, spontaneous, pinning factor, domain density, domain
coupling and reversibility fac
