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dc.contributor.advisor El Sheikh, Salah
dc.contributor.advisor Abd-Elmeguid, Mohsen Zeama, Mostafa Galal El-Dine
dc.creator Zeama, Mostafa Galal El-Dine 2011-05-31T13:31:41Z 2011-05-31T13:31:41Z 2011 Spring 2011-05-31T13:31:41Z
dc.description.abstract The high pressure solid state physics has become one of the most important physics branches now a days as it study the effect of the pressure on the material physical properties and what does the material do to get rid of this effect. One of the long-standing issues associated with strongly correlated 3d transition metal oxides (e.g. RMO3) is the microscopic origin of the metal insulator (MI) transition and the nature of the ground state. As in this type of materials the MI transition is driven by strong correlation effects associated with the electron-electron interaction and the interplay between charges, orbital and spin degrees of freedom. Here we use the change in the external pressure as a tool to tune electronic and magnetic properties of these systems by increasing the external pressure we change the bond length between the Metal and the Oxygen (dM-O) which will modify the effective band width, also it will affect on the bond angle between the Metal and the Oxygen (θM-O-M). For applying the external pressure we use 2 diamonds crystals in a setup called the Diamond Anvil cell (DAC) which has been developed over the year's since the first half of the 20th century till now. We prepare the cell with certain manner to allow the measurement of the resistivity of the sample and the structure properties using the x-ray diffraction method. For measuring the resistivity of the YbNiO3 under different pressures and temperatures we use a cryostat to control the temperature and reach a very low temperature, and we use the nanovoltmeter, melliammeter, and a current source to measure the electrical variables on the YbNiO3. For determining the crystal structure of the YbNiO3 and the effect of the pressure on it we use a high energy x-ray beam from the synchrotron and focus it on the sample then analyze the spectra to get the structure properties of the YbNiO3. When analyzing the data for the resistivity we found that the sample behave as insulator below certain pressure and as the pressure increase some metallic properties start to appear, so the sample is said to undergo an insulator metallic transition. When we investigate the crystal structure of the sample to see the cause of this transition and it's relation to the crystal structure of the sample we found that the structure phase transition take place at higher pressure value as for MI transition, which indicate that the insulator metal transition isn't accompanied by structure phase transition. en
dc.format.medium theses en
dc.language.iso en en
dc.rights Author retains all rights with regard to copyright. en
dc.subject High pressure en
dc.subject.lcsh Thesis (M.S.)--American University in Cairo en
dc.subject.lcsh Pressure transducers.
dc.subject.lcsh Transition metal oxides.
dc.subject.lcsh High pressure.
dc.title Effect of pressure on the electrical transport and structural properties of YbNiO3 en
dc.type Text en
dc.subject.discipline Physics en
dc.rights.access This item is available en
dc.contributor.department American University in Cairo. Dept. of Physics en

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  • Theses and Dissertations [1841]
    This collection includes theses and dissertations authored by American University in Cairo graduate students.

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