Atomic structure of (GeTe)m(Sb2Te3)n phase-change materials

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2014

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Homurlu, Sibel

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In this thesis, pulse phase resolved X-ray spectroscopy of four accretion powered millisecond pulsars which are IGR J00291+5934 , IGR J17498-2921 , XTE J0929-314 and XTE J1807-294 will be presented. Phase dependent changes during their outbursts will be checked for possible correlations of spectral parameters such as photon index and blackbody temperature with rotation phase using archive of Rossi X-ray Timing Explorer (RXTE) observations. In the analysis of IGR J17498-2921 in 2011 outburst , positive correlation is found between photon index and flux. In the analysis of XTE J0929-314 in 2002 outburst, negative correlation is found between photon index and blackbody temperature. In the analysis of XTE J1807-294 in 2003 outburst, about 150 days RXTE observation data is divided into 7 states, which consist of 3 flare and 4 non-flare states. In the first flare state analysis, negative correlation is found between blackbody temperature and photon index. In the second flare state analysis, positive correlation is found between blackbody temperature and photon index. In the second non-flare state analysis, positive correlation is found between flux and photon index. In the fourth non-flare state analysis, positive correlation is found between flux and photon index. On the other hand, correlation between blackbody temperature, photon index and flux is not found in the analysis of third flare state, first non flare state and third non-flare state analysis of XTE J1807-294 and in the analysis of IGR J00291+5934 in September 2008 outburst.

Subject Keywords

Density functionals., Molecular dynamics., Phase transformations (Statistical physics).

URI

http://etd.lib.metu.edu.tr/upload/12617823/index.pdf
https://hdl.handle.net/11511/23856

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Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

S. Homurlu, “Atomic structure of (GeTe)m(Sb2Te3)n phase-change materials,” M.S. - Master of Science, Middle East Technical University, 2014.