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Pattern Formation on Thin Metal-Layered Germanium
Pattern Formation on Thin Metal-Layered Germanium
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202104700
- ISBN
- 9798280776661
- DDC
- 530
- 저자명
- Wong, Yilin.
- 서명/저자
- Pattern Formation on Thin Metal-Layered Germanium
- 발행사항
- [Sl] : University of California, Los Angeles, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 182 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-12, Section: B.
- 주기사항
- Advisor: Zocchi, Giovanni.
- 학위논문주기
- Thesis (Ph.D.)--University of California, Los Angeles, 2025.
- 초록/해제
- 요약This dissertation presents three distinct research projects. The first investigates pattern formation - the spontaneous emergence of structure from initially homogeneous materials - a ubiquitous phenomenon in physics, chemistry, and biology. Specifically, we examine self-organized patterns that develop on germanium (Ge) surfaces coated with evaporated metal thin films. These patterns originate at surface defects (etch pits) and arise from the coupling between the pre-existing mechanical stress in the metal film and underlying chemical reactions. I begin by outlining the experimental protocol that yielded this solid-state pattern-formation system. I then catalog the diverse pattern topologies we have observed-supported by scanning-electron-microscopy (SEM) images, optical-microscope photographs, and profilometry measurements. Next, I analyze video-microscopy data to characterize the dynamics of the etch front. To quantify residual strain in both the "lotus" and logarithmic-spiral patterns, I measure cylindrical and conical thin-film roll-ups. Near the defect, screw dislocations produce a 1/x strain field that gives rise to logarithmic spirals; farther from the defect, the strain field becomes more uniform, yielding radially symmetric patterns. Because these patterns originate from a singularity, they follow the logarithmic-spiral equation with remarkable precision - a regularity that suggests a broader class of singularity-driven pattern-formation phenomena. I conclude with a brief discussion of future research directions for this system. The second project focuses on detection of far-infrared signal at 100 nK at room temperature. These fluctuations are driven at the complex interface among p-doped germanium, a nm metal layer, and an electrolyte. We show that heat is deposited at this interface by thermoelectric effects, and that the temperature is measured by monitoring the modulation of blackbody radiation emanating from the interface. In particular, the Debye layer on the electrolyte side of the interface governs much of the system's dynamics. From first-principles analysis of our data, we demonstrate that, in this configuration, the Debye layer behaves as a low-frequency transmission line. Moreover, the exceptional sensitivity of our setup enables further exploration of dissipation phenomena at the molecular scale. The third project adapts DNA-enzyme supramolecular constructs as biological probes to assess bending stiffness of short (∼ 10 nm long) synthetic nucleic acids. We obtain the first measurements of bending elasticity for DNA/PNA and DNA/LNA hybrids, which was previously inaccessible, and established that, in order of increasing bending stiffness, we find: DNA/RNA, DNA/DNA, DNA/LNA, DNA/PNA. We also probed the nonlinear elasticity regime of the coupled enzyme-nucleic acid molecules. We find our measurements consistent with the existence of a softening transition in the mechanics of the enzyme. This result suggests that nonlinearity may be a general property of proteins in their folded state.
- 일반주제명
- Condensed matter physics
- 일반주제명
- Biophysics
- 일반주제명
- Materials science
- 기타저자
- University of California, Los Angeles Physics 0666
- 기본자료저록
- Dissertations Abstracts International. 86-12B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520260202104700
■006m o d
■007cr#unu||||||||
■020 ▼a9798280776661
■035 ▼a(MiAaPQ)AAI32116144
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a530
■1001 ▼aWong, Yilin.
■24510▼aPattern Formation on Thin Metal-Layered Germanium
■260 ▼a[Sl]▼bUniversity of California, Los Angeles▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a182 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-12, Section: B.
■500 ▼aAdvisor: Zocchi, Giovanni.
■5021 ▼aThesis (Ph.D.)--University of California, Los Angeles, 2025.
■520 ▼aThis dissertation presents three distinct research projects. The first investigates pattern formation - the spontaneous emergence of structure from initially homogeneous materials - a ubiquitous phenomenon in physics, chemistry, and biology. Specifically, we examine self-organized patterns that develop on germanium (Ge) surfaces coated with evaporated metal thin films. These patterns originate at surface defects (etch pits) and arise from the coupling between the pre-existing mechanical stress in the metal film and underlying chemical reactions. I begin by outlining the experimental protocol that yielded this solid-state pattern-formation system. I then catalog the diverse pattern topologies we have observed-supported by scanning-electron-microscopy (SEM) images, optical-microscope photographs, and profilometry measurements. Next, I analyze video-microscopy data to characterize the dynamics of the etch front. To quantify residual strain in both the "lotus" and logarithmic-spiral patterns, I measure cylindrical and conical thin-film roll-ups. Near the defect, screw dislocations produce a 1/x strain field that gives rise to logarithmic spirals; farther from the defect, the strain field becomes more uniform, yielding radially symmetric patterns. Because these patterns originate from a singularity, they follow the logarithmic-spiral equation with remarkable precision - a regularity that suggests a broader class of singularity-driven pattern-formation phenomena. I conclude with a brief discussion of future research directions for this system. The second project focuses on detection of far-infrared signal at 100 nK at room temperature. These fluctuations are driven at the complex interface among p-doped germanium, a nm metal layer, and an electrolyte. We show that heat is deposited at this interface by thermoelectric effects, and that the temperature is measured by monitoring the modulation of blackbody radiation emanating from the interface. In particular, the Debye layer on the electrolyte side of the interface governs much of the system's dynamics. From first-principles analysis of our data, we demonstrate that, in this configuration, the Debye layer behaves as a low-frequency transmission line. Moreover, the exceptional sensitivity of our setup enables further exploration of dissipation phenomena at the molecular scale. The third project adapts DNA-enzyme supramolecular constructs as biological probes to assess bending stiffness of short (∼ 10 nm long) synthetic nucleic acids. We obtain the first measurements of bending elasticity for DNA/PNA and DNA/LNA hybrids, which was previously inaccessible, and established that, in order of increasing bending stiffness, we find: DNA/RNA, DNA/DNA, DNA/LNA, DNA/PNA. We also probed the nonlinear elasticity regime of the coupled enzyme-nucleic acid molecules. We find our measurements consistent with the existence of a softening transition in the mechanics of the enzyme. This result suggests that nonlinearity may be a general property of proteins in their folded state.
■590 ▼aSchool code: 0031.
■650 4▼aCondensed matter physics
■650 4▼aBiophysics
■650 4▼aMaterials science
■653 ▼aMolecular biophysics
■653 ▼aNon-linear physics
■653 ▼aPattern formation
■653 ▼aThermoelectric effects
■653 ▼aScanning-electron-microscopy
■690 ▼a0611
■690 ▼a0786
■690 ▼a0794
■71020▼aUniversity of California, Los Angeles▼bPhysics 0666.
■7730 ▼tDissertations Abstracts International▼g86-12B.
■790 ▼a0031
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17358424▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
