Growth and Characterization of BaSb: Alloys رسالة ماجستير

Abstract

In this thesis, BaSbz alloys are produced and characterised. The alloys which are prepared by the melting of the Ba and Sb in stoichiometric compositions in a vacuum of 10°5 mbar at 735 °%C are structurally and electrically investigated. Deep structural investigations with the help of x-ray diffraction, " Crystdiff " ," Treor 92" and " phywe measure 4 " software packages has shown that the alloys are composed of monoclinic structure (58.46%) and other minor phases (41.54%). The structural parameters indicated that the alloys are composed of nano crystallites and exhibit low percentage of stacking faults and low defect density. The morphology analysis which were carried out with scanning electron microscopy have shown that the alloys are of layered types and contains narrow cracks of lengths of 5.0 um. Electrically, the alloys are metal like p-type materials which exhibit temporary metal-insulator transitions at low temperatures. The AC analysis on the capacitance and conductance spectra which were measured in the frequency domain of (0.01-1.8) GHz have shown that the capacitance exhibits negative capacitance effect owing to the injection of holes being larger than electrons. In addition, modelling of the conductance spectra in the main frequency domain has shown that the BaSbo alloys are dominated by the correlated barrier hopping conduction at scattering times of picosecond scales . The electrical properties of the BaSb: alloys nominate them for use in circuits as

parasitic capacitance cancellers ,as noise reducers and as microwave cavities .