Article
Materials Science, Multidisciplinary
Y. Zhu, J. Liu, B. Wei, S. Xu, Y. Song, X. Wang, T-L Xia, J. Chen, G. J. Snyder, J. Hong
Summary: In this study, giant anharmonic phonon modes were observed in Mg3Bi2 single-crystal through experimental measurements and verified by calculations. It was found that the giant anharmonicity is associated with the asymmetric Bismuth 6s lone-pair electrons. This finding provides new insight into the low lattice thermal conductivity of Mg3Bi2 and lays the foundation for designing novel high-efficient thermoelectric materials.
MATERIALS TODAY PHYSICS
(2022)
Article
Multidisciplinary Sciences
Qiyang Sun, Bin Wei, Yaokun Su, Hillary Smith, Jiao Y. Y. Lin, Douglas L. Abernathy, Chen Li
Summary: The study investigates the impact of spin-phonon coupling on the phonon system through experiments and calculations. Anomalous scattering spectral intensity is identified in antiferromagnetic nickel (II) oxide, revealing strong spin-lattice correlations. Magnetic scattering signature is observed in acoustic phonons, and a modified scattering cross-section model is proposed.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Physics, Condensed Matter
Atsushi Togo, Hiroyuki Hayashi, Terumasa Tadano, Satoshi Tsutsui, Isao Tanaka
Summary: This study measured and calculated the longitudinal-optical mode phonon branches of KCl and NaCl using inelastic x-ray scattering (IXS) and first-principles phonon calculation. The calculated spectral functions provided higher resolutions and showed multiple peaks, while the LO modes along the Gamma-L paths were found to be disconnected.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Chemistry, Physical
Ekashmi Rathore, Rinkle Juneja, Debattam Sarkar, Subhajit Roychowdhury, Maiko Kofu, Kenji Nakajima, Abhishek K. Singh, Kanishka Biswas
Summary: This study achieves high thermoelectric performance in Ge-doped n-type PbS material by tuning the electronic structure and reducing thermal conductivity. The enhancement of covalency in chemical bonding and the introduction of nanometer-sized precipitates scatter heat-carrying phonons and lower the lattice thermal conductivity. Experimental results reveal low-frequency phonon modes and ultra-short phonon lifetime that contribute to the low thermal conductivity, while electron localization function analysis confirms the chemical bonding hierarchy and increased covalent bonding.
MATERIALS TODAY ENERGY
(2022)
Article
Chemistry, Physical
Koji Yoshida, Yusuke Sanada, Toshio Yamaguchi, Masato Matsuura, Hiromu Tamatsukuri, Hiroshi Uchiyama
Summary: This study investigated the translational, rotational, and phonon dynamics of water in zirconium oxide (ZrO2) nanofluid. The results revealed that the motion of water molecules becomes slower with increasing concentration of ZrO2, indicating an attractive interaction between water molecules and nanoparticles. Additionally, the sound velocity of the nanofluid was slightly higher compared to pure water. These findings suggest that the dynamics of water in the nanofluid differ from those in bulk systems, which may contribute to the enhanced thermal conductivity of the nanofluid.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Inorganic & Nuclear
Jiayong Zhang, Yongqiang Cheng, Alexander I. Kolesnikov, Jerry Bernholc, Wenchang Lu, Anibal J. Ramirez-Cuesta
Summary: The anharmonic phonon behavior in zirconium hydrides and deuterides has been investigated using inelastic neutron scattering and lattice dynamics calculations within the framework of density functional theory. The study found that anharmonicity in these materials originates from deviations of hydrogen potentials from quadratic behavior in certain directions and is apparent for higher-order excited vibrational states. Convolution of the eigenfrequencies with the instrument resolution qualitatively describes the anharmonic peaks in the experimental data.
Article
Crystallography
Randy Belanger, James Patrick Clancy, Sheetal Jain, Zahra Yamani, Yu-Chih Tseng, Young-June Kim
Summary: We present the results of inelastic neutron scattering (INS) measurements on the phonon dispersion relation in higher manganese silicides (HMSs). A large single crystal ingot of HMS is synthesized using a slow cooling technique, with Mn15Si26 identified as the primary phase. The sample consists of highly oriented crystallites as confirmed by neutron pole-figure study and thermal conductivity data. Our INS results generally agree with previous experimental and theoretical studies on phonons in HMS; however, we also observe some discrepancies, such as a 5 meV gap at the zone center and a softer dispersion relation for the low-lying twisting mode. We discuss the possible origins of these observations and their implications for the thermal properties of HMS.
Article
Materials Science, Multidisciplinary
Sara B. Isbill, Zach E. Brubaker, Ashley E. Shields, J. L. Niedziela
Summary: Optical vibrational spectroscopy is a promising noninvasive method for monitoring the mechanical properties of carbon fiber. Inelastic neutron scattering spectroscopy provides a fuller vibrational spectrum and can assist in the interpretation of optical vibrational spectra. Recent experiments have identified hydrogen defects in carbon fibers and density functional theory simulations have confirmed their assignments.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Chemistry, Applied
Tommy Hofmann, Danny Kojda, Haider Haseeb, Dirk Wallacher, Oleg Sobolev, Klaus Habicht
Summary: This article presents inelastic thermal neutron scattering experiments probing the phonon dispersion in mesoporous silicon with 8 nm pores. The study reveals that phonon group velocities in highly-crystalline silicon are not modified by nanostructuring down to sub-10 nanometer length scales in mesoporous silicon, and there is apparently no effect of structuring on the elastic moduli. No evidence of phonon-softening is found in topologically complex, geometrically disordered mesoporous silicon in contrast to silicon nanotubes and nanoribbons.
MICROPOROUS AND MESOPOROUS MATERIALS
(2021)
Article
Chemistry, Inorganic & Nuclear
Duncan H. Moseley, Zhiming Liu, Alexandria N. Bone, Shelby E. Stavretis, Saurabh Kumar Singh, Mihail Atanasov, Zhengguang Lu, Mykhaylo Ozerov, Komalavalli Thirunavukkuarasu, Yongqiang Cheng, Luke L. Daemen, Daphne Lubert-Perquel Laboratory, Dmitry Smirnov, Frank Neese, A. J. Ramirez-Cuesta, Stephen Hill, Kim R. Dunbar, Zi-Ling Xue
Summary: A comprehensive investigation of magnetic excitations in the single-molecule magnet Co(AsPh3)2I2 was conducted using inelastic neutron scattering, far-IR magneto-spectroscopy, and Raman magneto-spectroscopy. The results accurately determined the magnetic excited level and the interaction between magnetic excitation and phonon modes.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Markos Poulos, Stefanos Giaremis, Joseph Kioseoglou, John Arvanitidis, Dimitris Christofilos, Sotirios Ves, Markus P. Hehlen, Neil L. Allan, Chris E. Mohn, Konstantinos Papagelis
Summary: Inelastic neutron scattering measurements of Y3Al5O12 were presented, with comparison of neutron-weighted phonon density-of-states and optical phonon frequencies to atomistic calculations within the Quasi-Harmonic Approximation. The phonon-related thermodynamic and elastic properties calculated within the QHA showed excellent agreement with experimental data.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2022)
Article
Chemistry, Inorganic & Nuclear
Aris Chatzidimitriou-Dreismann
Summary: The modern quantum theory of correlations predicts and reveals new counter-intuitive dynamical effects of hydrogen in nano-structured materials, which are important for both basic research and technological applications. Experimental observations of hydrogen molecules in carbon nanotubes show violations of standard conservation laws and significantly reduced inertia, suggesting the contribution of quantum systems to the translational dynamics and transport of hydrogen in these materials. This insight has potential implications for the design of optimized materials for hydrogen adsorption and transport in fields such as fuel cells and hydrogen storage.
ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES
(2022)
Article
Materials Science, Multidisciplinary
Shuonan Chen, Devin Coleman, Douglas L. Abernathy, Arnab Banerjee, Luke L. Daemen, Lorenzo Mangolini, Chen W. Li
PHYSICAL REVIEW MATERIALS
(2020)
Article
Physics, Multidisciplinary
Junxue Li, Haakon T. Simensen, Derek Reitz, Qiyang Sun, Wei Yuan, Chen Li, Yaroslav Tserkovnyak, Arne Brataas, Jing Shi
PHYSICAL REVIEW LETTERS
(2020)
Article
Materials Science, Multidisciplinary
Frank Angeles, Qiyang Sun, Victor H. Ortiz, Jing Shi, Chen Li, Richard B. Wilson
Summary: Interfaces play a crucial role in governing the thermal performance of nanoscale devices and nanostructured materials. Research has shown that the thermal boundary conductance between different materials ranges from 50 to 300 MW m(-2) K-1, with variations at different temperatures. This knowledge is essential for accurately modeling the temperature response of nanoscale devices and materials.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Junyan Liu, Timothy A. Strobel, Haidong Zhang, Doug Abernathy, Chen Li, Jiawang Hong
Summary: The study shows that flat phonon bands in BC8-Si play a critical role in reducing lattice thermal conductivity by enlarging the phonon-phonon scattering phase space. This provides insights into the significant reduction of lattice thermal conductivity in this novel silicon allotrope.
MATERIALS TODAY PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Bin Wei, Junyan Liu, Qingan Cai, Ahmet Alatas, Ayman H. Said, Meihua Hu, Chen Li, Jiawang Hong
Summary: An exceptional case of thermal conductivity anisotropy in layered pentagonal PdSe2 is reported. The thermal conductivity along the b-axis is surprisingly much greater than along the a-axis. The high anisotropy is attributed to the low-energy phonons along the a-axis and the different buckling structures between the a-axis and the b-axis.
MATERIALS TODAY PHYSICS
(2022)
Article
Physics, Multidisciplinary
Bin Wei, Qingan Cai, Qiyang Sun, Yaokun Su, Ayman H. Said, Douglas L. Abernathy, Jiawang Hong, Chen Li
Summary: By measuring the Matryoshka phonon dispersions, insights into the anisotropic thermal conductivity of semiconducting alpha-GaN have been gained, showing how phonon topology affects thermal transport in the material. This study demonstrates the importance of understanding lattice dynamics for effective thermal management in electronic devices.
COMMUNICATIONS PHYSICS
(2021)
Article
Chemistry, Physical
Shuonan Chen, Devin Coleman, Douglas L. Abernathy, Arnab Banerjee, Lorenzo Mangolini, Chen Li
Summary: Phonon, as a momentum carrier, plays an important role in the photoluminescence of silicon nanocrystals. In this research, inelastic neutron scattering was used to study the effects of particle size, oxidation, and temperature on phonon dynamics in silicon nanocrystals. It was found that the transverse acoustic phonon modes are more sensitive to particle size, oxidation, and temperature compared to optical phonon modes. The changes in phonon dynamics have the largest impact on vibrational entropy and free energy of silicon nanocrystals at intermediate temperatures.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Multidisciplinary Sciences
Qiyang Sun, Bin Wei, Yaokun Su, Hillary Smith, Jiao Y. Y. Lin, Douglas L. Abernathy, Chen Li
Summary: The study investigates the impact of spin-phonon coupling on the phonon system through experiments and calculations. Anomalous scattering spectral intensity is identified in antiferromagnetic nickel (II) oxide, revealing strong spin-lattice correlations. Magnetic scattering signature is observed in acoustic phonons, and a modified scattering cross-section model is proposed.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Nanoscience & Nanotechnology
Songrui Hou, Bo Sun, Fei Tian, Qingan Cai, Youming Xu, Shanmin Wang, Xi Chen, Zhifeng Ren, Chen Li, Richard B. Wilson
Summary: This study investigates the relationship between thermal conductivity and pressure in boron arsenide (BAs) and finds that the thermal conductivity of BAs is independent of pressure below 30 GPa. This result demonstrates the significant relationship between phonon dispersion properties and phonon scattering rates.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Instruments & Instrumentation
B. Haberl, D. G. Quirinale, C. W. Li, G. E. Granroth, H. Nojiri, M. -E. Donnelly, S. V. Ushakov, R. Boehler, B. L. Winn
Summary: This article describes three concepts for the application of multi-extreme conditions under in situ neutron scattering. These concepts include a neutron diamond anvil cell made from a non-magnetic alloy, laser-heating of a neutron diamond cell using a defocused CO2 laser, and a hybrid levitator for measuring solids and liquids. The application of these concepts will provide a broader parameter space for neutron scattering experiments.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Materials Science, Multidisciplinary
Qingan Cai, Bin Wei, Qiyang Sun, Ayman H. Said, Chen Li
Summary: Understanding the lattice dynamics of two-dimensional layered materials is crucial for regulating their thermal properties. In this study, the lattice dynamics of tungsten diselenide (WSe2) was comprehensively investigated using inelastic X-ray scattering and first-principles calculations, revealing monolayer-like lattice dynamics in the bulk WSe2. By performing the first temperature-dependent phonon dispersion measurement, the mode Gruneisen parameters of bulk WSe2 were obtained, showing better agreement with calculations on the monolayer system. This observation indicates that the lattice dynamics in bulk WSe2 exhibit characteristics of monolayers, providing valuable insights into the thermal properties of WSe2-based devices.
MATERIALS TODAY PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Yaokun Su, Hillary L. Smith, Matthew B. Stone, Douglas L. Abernathy, Mark D. Lumsden, Carl P. Adams, Chen Li
Summary: In this study, an unconventional scattering anomaly was reported in FeGe2, demonstrating near-perfect magnetic frustration and the emergence of unexpected two-dimensional magnetic order in the quasi-one-dimensional structure. This finding is of great significance for understanding exotic quantum phenomena in materials.
Article
Chemistry, Physical
Qingan Cai, Michael McIntire, Luke L. Daemen, Chen Li, Eric Chronister
Summary: The study on para-terphenyl using inelastic neutron scattering at temperatures from 10 to 200 K and pressures from the ambient pressure to 1.51 kbar revealed strong anharmonic phonon dynamics, with no phase transition observed in the region of 0-1.51 kbar and 10-30 K. The overall lattice dynamics remained similar up to 200 K under ambient pressure, suggesting that the boundary between the ordered triclinic phase and the third solid phase reported at lower temperatures and higher pressures was not within the scope of this study.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
D. S. Kim, O. Hellman, N. Shulumba, C. N. Saunders, J. Y. Y. Lin, H. L. Smith, J. E. Herriman, J. L. Niedziela, D. L. Abernathy, C. W. Li, B. Fultz