Essays about: "phonon"

Showing result 1 - 5 of 30 essays containing the word phonon.

  1. 1. First principles investigation of the thermal conductivity of Zr, ZrC, and ZrN

    University essay from KTH/Fysik

    Author : Daniel Karlsson; [2023]
    Keywords : Electron-phonon interaction; Density functional theory; Boltzmann transport equation; first-principles; thermal conductivity; electrical resistivity; Abinit; Phono3py; Elektron-fononväxelverkan; täthetsfunktionalteori; Boltzmanns transportekvation; värmeledningsförmåga; elektrisk resistivitet; Abinit; Phono3py;

    Abstract : The thermal conductivity and electrical resistivity of Zr, ZrC, and ZrN were calculated using first-principles density functional theory (DFT) and the Boltzmann transport equation. The electron-phonon scattering was modeled via the self-energy relaxation time approximation (SERTA), and the phonon-phonon scattering via the analogous single-mode relaxation time approximation (SMRTA). READ MORE

  3. 2. Phonons in 1-D Graphene Nanoribbons Probed with Raman Spectroscopy : Unraveling Fundamental Properties in 9-atom-wide Graphene Nanoribbons

    University essay from KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Author : Angel Victor Labordet Alvarez; [2023]
    Keywords : 9-armchair graphene nanoribbons 9-AGNRs ; polarization Raman Spectroscopy PRS ; temperature-dependent Raman spectroscopy; thermal sensitivity; thermal stability; Grüneisen parameter χ ; anharmonicities; vibrational modes G; D; RBLM .; 9-armchair grafen nanoribbons 9-AGNRs ; polarisation Raman spektroskopi PRS ; temperaturberoende Raman spektroskopi; termisk känslighet; termisk stabilitet; Grüneisen parameter χ ; anharmoniciteter; vibrationslägen G; D; RBLM .;

    Abstract : This report employs advanced Raman spectroscopy techniques to investigate the fundamental properties of 9-AGNRs comprehensively. It is divided into two main sections addressing distinct aspects of 9-AGNR behavior. In the first section, Polarization Raman spectroscopy (PRS) probes phonon mode symmetries in 9-AGNRs. READ MORE

  4. 3. Time-resolved x-ray diffraction study of longitudinal optical phonons in zincblende semiconductors

    University essay from Lunds universitet/Atomfysik; Lunds universitet/Fysiska institutionen

    Author : Lassi Linnala; [2022]
    Keywords : femtosecond THz radiation; ultrafast x-ray diffraction; pump-probe; longitudinal optical phonons; zincblende semiconductors; anharmonic decay; density functional perturbation theory; Physics and Astronomy;

    Abstract : Anharmonic decay of longitudinal optical (LO) phonons in zincblende semiconductors is not at present well characterized due to the polar and many-body nature of the problem. Femtosecond THz radiation offers a novel route to this study, as the interaction of this radiation is directly with the phonon lattice and these THz excited phonons do not have enough energy to excite electrons over the band gap. READ MORE

  5. 4. Synthesis and thermoelectric properties of Cr1-xMexN (Me = Mo, V)

    University essay from Linköpings universitet/Tunnfilmsfysik

    Author : Victor Rutberg; [2022]
    Keywords : Chromium nitride; thin films; thermoelectrics; physical vapour deposition; medium entropy alloy;

    Abstract : Among emerging materials systems for thermoelectric applications, the early transition-metal nitrides based on ScN and CrN show unexpectedly promising properties. These properties are determined by high Seebeck coefficient, low thermal conductivity, and high electrical conductivity. READ MORE

  6. 5. Study on the Electronic Band Structure of the Spinel Superconductor LiTi2O4

    University essay from KTH/Tillämpad fysik

    Author : Gaia Di Berardino; [2022]
    Keywords : LiTi2O4; anomalous superconductivity; density functional theory; ARPES; electronic band structure; PLD; condensed matter physics; material science; LiTi2O4; okonventionell supraledning; funktionell densitetsteori; ARPES; elektronisk bandstruktur; PLD; kondenserade materiens fysik; materialvetenskap;

    Abstract : This master’s thesis focuses on investigating the electronic properties of the superconducting spinel compound LiTi2O4 by means of computational and experimental effort. The title compound has been extensively studied in the past years, being the only known superconducting spinel oxide with relatively high Tc = 11.5 K. READ MORE