Show simple item record

dc.contributor.advisorDeymier, Pierreen_US
dc.contributor.authorLee, Chong Yong.*
dc.creatorLee, Chong Yong.en_US
dc.date.accessioned2011-10-31T17:31:55Z
dc.date.available2011-10-31T17:31:55Z
dc.date.issued1990en_US
dc.identifier.urihttp://hdl.handle.net/10150/185239
dc.description.abstractWe have introduced two different techniques in this paper to investigate the high Tc superconductor BaK BiO₃. The first one is the rigid-ion molecular dynamics model to calculate classical properties of the crystal. This method provides the ionic anisotropic vibrational spectra. It is found that the oxygen modes dominate the vibrational spectrum from 150 cm⁻¹ up to 820 cm⁻¹. An increase in the number of substituted K around an oxygen favors high frequency vibrational modes. We have also determined by experiment IR spectrum. The absorption peaks are between 380 to 880 cm⁻¹. Our experimental and computational data are in good agreement in the high frequency region. The second technique used to investigate this high Tc superconductor is based on a quantum path integral molecular dynamics. It has been applied for the first time to the determination of electron-phonon interaction energy. We estimate the electron phonon coupling constant at about 1.34. This value represents a weak to moderate electron-phonon coupling in Ba₁₋ₓKₓBiO₃ in agreement with current views of this pairing mechanism in this material.
dc.language.isoenen_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.titleElectron-phonon interaction in barium-potassium-bismuth-oxygen superconductor by quantum path integral molecular dynamics (QPIMD).en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
thesis.degree.grantorUniversity of Arizonaen_US
thesis.degree.leveldoctoralen_US
dc.contributor.committeememberStark, Royalen_US
dc.contributor.committeememberParmenter, Robert H.en_US
dc.contributor.committeememberJust, Kurten_US
dc.contributor.committeememberVuillemin, Josephen_US
dc.identifier.proquest9111926en_US
thesis.degree.disciplinePhysicsen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.namePh.D.en_US
refterms.dateFOA2018-08-20T07:56:24Z
html.description.abstractWe have introduced two different techniques in this paper to investigate the high Tc superconductor BaK BiO₃. The first one is the rigid-ion molecular dynamics model to calculate classical properties of the crystal. This method provides the ionic anisotropic vibrational spectra. It is found that the oxygen modes dominate the vibrational spectrum from 150 cm⁻¹ up to 820 cm⁻¹. An increase in the number of substituted K around an oxygen favors high frequency vibrational modes. We have also determined by experiment IR spectrum. The absorption peaks are between 380 to 880 cm⁻¹. Our experimental and computational data are in good agreement in the high frequency region. The second technique used to investigate this high Tc superconductor is based on a quantum path integral molecular dynamics. It has been applied for the first time to the determination of electron-phonon interaction energy. We estimate the electron phonon coupling constant at about 1.34. This value represents a weak to moderate electron-phonon coupling in Ba₁₋ₓKₓBiO₃ in agreement with current views of this pairing mechanism in this material.


Files in this item

Thumbnail
Name:
azu_td_9111926_sip1_m.pdf
Size:
2.615Mb
Format:
PDF
Description:
azu_td_9111926_sip1_m.pdf

This item appears in the following Collection(s)

Show simple item record