الفهرس | Only 14 pages are availabe for public view |
Abstract In this thesis a different experimental study of adding Al2O3 to the prepared La0.7Ba0.3MnO3 via solid state reaction method to acquire (La0.7Ba0.3MnO3)1-x/(Al2O3)x composites, where x=0.00, 0.025, 0.050, 0.075, 0.10, 0.125 & 0.150 wt %. The physical properties especially: structural, magneto-transport, thermoelectric power and magnetic properties as a function of composition and annealing temperature were studied. On other side, the annealing temperature was taken as a variable parameter to study its influence on before mentioned physical properties of the considered composites. An analysis of the structural properties was carried out by means of X-ray diffraction, the Rietveld technique and Scanning Electron Microscope (SEM). The doping process did not change the structural properties. The structural properties are characterized by a single-phase rhombohedral structure with a space group ( ̅ ). The crystallite sizes (determined from XRD) are smaller than the grain sizes (determined from SEM). This difference is probably due to the fact that an LBMO grain consists of severa |