MARC보기
LDR00000nam u2200205 4500
001000000432730
00520200224134451
008200131s2019 ||||||||||||||||| ||eng d
020 ▼a 9781687983572
035 ▼a (MiAaPQ)AAI13884234
040 ▼a MiAaPQ ▼c MiAaPQ ▼d 247004
0820 ▼a 530
1001 ▼a Konstantinova, Tatiana.
24510 ▼a Electron-lattice Interactions in Functional Materials Studied by Ultrafast Electron Diffraction.
260 ▼a [S.l.]: ▼b State University of New York at Stony Brook., ▼c 2019.
260 1 ▼a Ann Arbor: ▼b ProQuest Dissertations & Theses, ▼c 2019.
300 ▼a 130 p.
500 ▼a Source: Dissertations Abstracts International, Volume: 81-05, Section: B.
500 ▼a Advisor: Zhu, Yimei.
5021 ▼a Thesis (Ph.D.)--State University of New York at Stony Brook, 2019.
506 ▼a This item must not be sold to any third party vendors.
506 ▼a This item must not be added to any third party search indexes.
520 ▼a Ultrafast Electron Diffraction (UED) provides a unique tool for separating the role of the crystal lattice in many-body interactions in complex materials. This technique utilizes short pulses of high-energy electrons to get time-series of diffraction patterns that reveal nonequilibrium structural evolution in a photoexcited sample. Through analysis of changes in the diffraction patterns, a full picture of atomic rearrangement can be reconstructed. The characteristic time scales of the lattice dynamics provide a clue to the processes that govern them.In this work, UED is applied to study diverse interactions between lattice and electronic degrees of freedom in superconducting Bi-2212 and FeSe single crystals. On the example of Bi-2212 we have revealed how energy, absorbed by electrons from a laser pulse, is transferred to and redistributed between various atomic vibrations in case of preferential electron-phonon coupling, which is common for a number of functional quantum materials, such as graphene and charge density wave compounds.Observation of nonequilibrium lattice dynamics in FeSe crystals with UED revealed lattice distortions that locally break the lattice symmetry, a feature that gets lost when probed at equilibrium with large-scale tools, such as Rietveld refinement. We have demonstrated that the distortions couple to electronic degrees of freedom (nematic fluctuations) and are involved in the formation of the nematic phase, deemed precursor of superconductivity in Fe-based compounds. This thesis shows how useful information about lattice dynamics can be extracted by analyzing every aspect of the diffraction pattern: intensity of Bragg peaks of different kinds (long-range crystal orders), intensity of diffuse scattering (phonons and short-range lattice imperfections), peak shape (domain size). The results of this work demonstrate how UED data can provide new insights on the plethora of interactions between crystal lattice and electronic degrees of freedom.
590 ▼a School code: 0771.
650 4 ▼a Physics.
690 ▼a 0605
71020 ▼a State University of New York at Stony Brook. ▼b Physics.
7730 ▼t Dissertations Abstracts International ▼g 81-05B.
773 ▼t Dissertation Abstract International
790 ▼a 0771
791 ▼a Ph.D.
792 ▼a 2019
793 ▼a English
85640 ▼u http://www.riss.kr/pdu/ddodLink.do?id=T15491353 ▼n KERIS ▼z 이 자료의 원문은 한국교육학술정보원에서 제공합니다.
980 ▼a 202002 ▼f 2020
990 ▼a ***1008102
991 ▼a E-BOOK