الفهرس 
Intrinsic Properties of Ferrites with Spinel Structure
Experimental TechniquesOnly 14 pages are availabe for public view
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Abstract
Cu1-xZnx+yZryFe2-2yO4(Cu-Zn-Zr ferrite) series of compositions with x=(zero, 0.4, 0.6, 0.8, 1)when y=(0.05, and 0.1) nanoparticles were synthesized using
citrate sol-gel method. The prepared nanoparticles were characterized by X-ray diffraction(XRD)and transmission electron microscopy(TEM).Lattice parameter,bulk density, theoretical density, and porosity were measured for (Cu-Zn-Zr ferrite)samples. The XRD pattern indicated that the average crystallite size found from 18-
30 nm and from 17-24 nm, while the average particle size from TEM images are ranging from 21-39 nm and from 18-24 nm for y=(0.05 and 0.1)respectively. The grains were observed confirming the crystalline structure of the ferrite which was detected by X-Ray diffraction. The grain size of our samples are ranging from 1.82 to 4.576 μm for Zr=0.1 and from 2.436 to 4.6177 μm for Zr=0.05. The FTIR absorption spectra for in the range of 200-4000 cm-1. The lower frequency absorption band ʋ2 lies near the frequency 418cm-1 and the higher absorption band ʋ1 lies around the frequency 594 cm-1. Magnetic hysteresis loop measurements illustrate that materials exhibit as soft ferrite properties at low Zn content, while at
higher Zn content all materials behave as superparamagnetic materials without any saturation magnetization Ms. The initial magnetic permeability ( ) at two
frequencies 1 KHz and 10 KHz as a function of temperature was measured. A
sudden change in appear around Curie temperature, making our samples good
candidates for Magnetic Temperature Transducer(MTT)devices. The DC resistivity as a function in reciprocal temperature k-1for the two series y=0.05
and y=0.1 are studied. The resistivity decreases linearly with increasing temperature within the given range of temperature 666 k for all samples. The decrease in dc resistivity is explained by the thermally activated mobility of the bond charge carriers that are hopping between . The value of dc resistivity was found to increase with increasing Zn content in nano Cu Ferrite, which may be attributed to the decrease of content in tetrahedral site. The dielectric constant
of all samples nearly independent on temperature through the range 450 to 600 oK for all samples and the rapid increase with a peak at temperature near the curie temperature. The dielectric loss (tan ) was found to increase by increasing temperature, which may be related to the increase of Ac conductivity.