الفهرس 
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Abstract
This thesis is studying the physical properties including structure and magnetic properties of several magnetic nanomaterials. The thesis consists of two groups
The first group consists of preparing and characterizing Co0.2Fe2.8O4 was prepared with different concentrations of polyethylene glycol 6000 (0, 10, 20, 30, and 40%). X-ray diffraction was measured and it was found that the samples were formed in a single phase without any additional phases and the crystallite size ranged from 8 to 11 nanometers, the materials were measured using Fourier transform infrared spectroscopy to ensure the formation of ferrite. The samples were also imaged using a transmission electron microscope and it was found that the particle size was very small, ranging between 10,11,12 nanometers. It was found that the higher the polymer concentration, the greater the separation between the particles In this study, synchrotron radiation and its distinctive characteristics were used to measure:
X-ray absorption fine structure (XAFS), was done at the absorption edge of the iron element (7112 eV), in order to study the electronic and atomic composition of the materials around the iron atom and gave important information about the cation distribution. Then the magnetic properties of the materials were measured using the Vibrating sample magnetometer (VSM), through which the magnetic behavior of the prepared composites was studied and the values of magnetic coefficients such as saturation magnetization (Ms), remanent magnetisation (Mr), and the coercive field or impedance (Hc) were calculated, which determine their magnetic importance in various applications which revealed the ferromagnetic behavior of the samples. The magnetic measurements were done at room temperature. The size of the nanomaterials was measured using the Zeta device, as well as the potential of the prepared nanomaterials, and it was found suitable to be used in various biological applications.
The samples were imaged with an MRI device to find out the best samples in MR imaging, It was found that the sample with a concentration of 30% of the polymer is the best in terms of imaging as it has the highest blackness degree in MRI T2 weighted image.
Also, the toxicity level of the same sample was also measured and found acceptable, according to internationally recognized standards.
The Second group It was found that the optimum sample in the first group is cobalt iron oxide sample with a concentration of 30% of the polymer, so this concentration was approved, and the second group consists of M0.2Fe2.8O4 /30% PEG with molecular weight 6000 where (M=Fe2+, Mn2+, and Cu2+) were prepared by using sonochemical method. The formation of the material was confirmed with the expected crystal structure using an X-ray diffraction device which confirmed the single phase formation. The samples were also measured using the Fourier transformer infrared spectroscopy to ensure the proper chemical composition of the materials and to know the chemical bonds between the elements within the material and revealed the ferrite formation. The samples were also imaged using a high-resolution transmission electron microscope to measure the particle size and determine the particle shape, X-ray photoelectron spectroscopy was measured and confirmed the existence of the electronic structure of the samples , the samples were also measured by using zeta potentiometer, zeta sizer, vibrating sample magnetometer, toxicity measurements, and magnetic resonance imaging.
It was found that Compatibility and complementarity between all results obtained using different characterization techniques, the success of the samples prepared and the samples described in a comprehensive description in biomedical applications, including magnetic resonance imaging, and it was found that in the first group Co0.2Fe2.8O4 sample with a concentration of 30% of the polymer is the optimum sample to be used as a contrast agent for Magnetic resonance imaging device (MRI). The success of preparing the samples of the second group, and they were comprehensively described. It was found that the best sample in terms of image quality in the magnetic resonance device owned by manganese iron oxide sample with 30% of polyethylene glycol. Also, the toxicity level of the same sample was measured and found acceptable