الفهرس 
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Abstract
This thesis focuses on Pulsed Laser Deposition (PLD) system,fabrication of Gd- doped Ti Co ferrite thin films and their characterization. The thin films were characterized in details by bemploying structural X- Ray Diffraction (XRD), Raman spectroscopy and Vibrating Sample Magnetometer (VSM) measurementsFirstly, Gd-doped Ti Co ferrite powder was fabricated by the standard ceramic technique followed by studying of the structure and magnetic properties. XRD and Raman spectroscopy confirmed the polycrystalline structure of two phases, which are cubic inverse spinel and perovskite structures, with the appearance of the secondary phase. VSM measurement indicated that the hysteresis loop has soft magnetic behavior. The prepared powder was then pressed in the form of a pellet to be used as a target for preparing thin films by PLD.Secondly, Gd-doped Ti Co ferrite thin films were then prepared by PLD on two different substrates (Si 100) and quartz) at two deposition times (30 min and 120 min) under the following conditions: Nd: YAG laser with 1064 nm, 6 ns pulse duration, 10 Hz repetition rate, at pressure 2x10-6 Torr and distance between target and substrate was held at 4 cm. Then, these thin films were annealed at different temperatures (500°C, 700°C and 900 °C). Average thicknesses of these thin films were ~ 126 nm and ~ 515 nm at deposition times 30 min and 120 min, respectively. These thin films were characterized by XRD, Raman, and VSM.Thirdly, Gd-doped Ti Co ferrite thin films were deposited on a quartz substrate at two deposition times (30 min and 120 min), XRD results observed that as-deposited thin films was amorphous at both deposition times. Single phase of cubic inverse spinel structure was formed in the case of deposition time 30 min, while polycrystalline cubic inverse spinel structure, with the appearance of secondary phase at 900 °C, were formed in the case of deposition time 120 min. The crystallite size increased with increasing annealing temperatures. Raman spectra of these thin films on quartz were not detectable due to highly fluorescent and very weak Raman signal. VSM measurement of thin films indicated the absence of magnetization of thin films at 30 min; it may be used amorphous substrate. While thin films at 120 min exhibited an increase magnetization and reduction of the coercive field with increasing annealing temperatureFourthly, Gd-doped Ti Co ferrite thin films deposited on Si (100) substrate at two deposition times (30 min and 120 min). It was found that XRD results of thin films were deposited on Si (100) is the as that of thin films were deposited on quartz. Raman spectra of thin films were deposited on Si (100) observed, unlike XRD results, all thin films are polycrystalline of two phases, which are cubic inverse spinel and perovskite, and the appearance secondary phase at 900 °C in case of deposition time 120 min. While VSM measurement of thin films, were deposited on Si (100), was different that of thin films were deposited on quartz, according to the type of substrate. where Si (100) substrate has a single crystal and quartz substrate has amorphous. An increase of magnetization and decrease of the coercive field with increasing annealing temperatures was occurred incase of deposition time 30 min. While thin films at 120 min observed an increase of magnetization and coercive field with increasing annealing temperatures and decrease coercive field at 700 C.from all, the variation of the coercive field as a function of annealing temperature may be suitable for various applications. For example, the thin films with a large coercive field may be useful for a magnetic recording media and the thin films with the low coercive field may be used as a magnetic head material or for microwave devices applications.