Article
Multidisciplinary Sciences
Andrei Zakharov, Daniel A. Beller
Summary: This study investigates the potential of shaping multistability and shape morphing in flexible crystalline membranes using glide mobility of dislocations. The results show that the relative and absolute stability of competing states strongly depend on control parameters, and demonstrate a broad design space for controllable and reconfigurable colloidal tube geometries.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Mechanics
Jerome Colin
Summary: The equilibrium positions of an edge dislocation in a freestanding thin film under uniaxial stress were investigated using Peach-Koehler force calculation. It was found that depending on the inclination angle of the dislocation gliding plane, one stable and two unstable equilibrium positions exist when the film is stress-free. A critical angle was identified where only one unstable equilibrium position remains. The effects of compressive and tensile stress on the dislocation stability in the film were analyzed, and the critical stress values were determined where the dislocation no longer has a stable equilibrium.
ARCHIVE OF APPLIED MECHANICS
(2023)
Article
Mathematics, Applied
Thomas Hudson, Filip Rindler
Summary: This work introduces a model for large-strain, geometrically nonlinear elasto-plastic dynamics in single crystals, where the plastic dynamics are entirely driven by the movement of dislocations. The authors propose a novel geometric language to describe the movement of dislocations and couple it to plastic flow. The energetics and dissipation relationships in the model are derived from first principles. The authors further show that the model recovers several known laws and discuss how other effects could be incorporated.
MATHEMATICAL MODELS & METHODS IN APPLIED SCIENCES
(2022)
Article
Materials Science, Multidisciplinary
Daniel N. Blaschke
Summary: This work aims to derive a general anisotropic solution for pure screw dislocations applicable to slip systems featuring a reflection symmetry in anisotropic crystals, in order to study pure screw dislocations without mixing with edge dislocations. However, further generalizations to arbitrary mixed dislocations as well as regularizations of the dislocation core are left for future work.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Materials Science, Multidisciplinary
Petr Grigorev, Alexandra M. Goryaeva, Mihai-Cosmin Marinica, James R. Kermode, Thomas D. Swinburne
Summary: Calculations of dislocation-defect interactions are difficult due to the limitations of ab initio simulations. Hybrid methods, such as linear-in-descriptor machine learning potentials, offer a solution by embedding ab initio simulations in an empirical medium. This allows for more accurate modeling of dislocation migration pathways and defect geometries.
Article
Chemistry, Physical
Daniel N. Blaschke, Khanh Dang, Saryu J. Fensin, Darby J. Luscher
Summary: We discuss the theoretical solution to the differential equations governing accelerating edge dislocations in anisotropic crystals. This is crucial for understanding high-speed dislocation motion, including the unresolved question of transonic dislocation speeds, and subsequent high-rate plastic deformation in metals and other crystals.
Article
Multidisciplinary Sciences
Qingsong Pan, Liangxue Zhang, Rui Feng, Qiuhong Lu, Ke An, Andrew Chihpin Chuang, Jonathan D. Poplawsky, Peter K. Liaw, Lei Lu
Summary: By introducing gradient nanoscaled dislocation cell structures in stable single-phase HEAs, enhanced strength can be achieved without apparent loss of ductility. The gradient structure induces the formation of high-density tiny stacking faults and twins, contributing to improved plasticity, increased strength, and work hardening.
Review
Physics, Condensed Matter
Daniel N. Blaschke
Summary: This short review provides a concise overview of the limiting velocities for dislocations of arbitrary character in general anisotropic crystals, and how to efficiently compute them, either analytically or numerically.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Materials Science, Multidisciplinary
K. C. Le, S. L. Dang, H. T. Luu, N. Gunkelmann
Summary: This paper presents a modified version of the thermodynamic dislocation theory, which can fit the stress-strain curves of bcc crystals niobium, tantalum, tungsten, and vanadium over a wide range of temperatures and strain rates by employing a small set of physics-based material parameters identified through large scale least squares analysis.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
Samuel Amstutz, Nicolas Van Goethem
Summary: This work focuses on modeling the incompatible deformations of solid continua caused by microscopic defects such as dislocations. The approach is based on a geometric description of the medium using the strain tensor, and the representation of internal forces using zeroth- and second-order strain gradients in an infinitesimal framework. At the same time, energetic arguments are used to monitor the corresponding moduli.
MATHEMATICS AND MECHANICS OF SOLIDS
(2023)
Article
Nanoscience & Nanotechnology
Lin Tian, R. Lakshmi Narayan, Kun Zhou, Rita Babicheva, Upadrasta Ramamurty, Zhi-wei Shan
Summary: The study found that the monolithic BCC crystalline phase and amorphous phase have high yield strains due to small length scale effects, but undergo negligible post-yield elongation before failure. However, the ductility of the bilaminate composite is significantly higher when the thickness of its amorphous portion is <100 nm.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Hiroyuki Y. Yasuda, Yusuke Yamada, Ken Cho, Takeshi Nagase
Summary: The deformation behavior of equiatomic HfNbTaTiZr high entropy alloy was found to be influenced by 1/2<111> screw dislocations, similar to body centered cubic metals. An anomaly in yield stress was observed in the alloy solutionized at 1473 K, with the stress decreasing rapidly at lower temperatures and increasing at 873 K. The microstructure of the alloy strongly depended on annealing temperature, with phase separation and precipitation of different phases observed at different temperatures. Dynamic precipitation of the HCP phase was suggested to be responsible for the yield stress anomaly.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Review
Engineering, Environmental
Zhiao Zhuo, Jiawei Lin, Jinhe Li, Songgu Wu, Weiguo Hu, Junbo Gong
Summary: The emergence of flexible molecular crystals opens up possibilities for wide-ranging applications, but the relationship between crystal structure and mechanical properties remains to be explored. Weak dispersive interactions play a crucial role in designing mechanically flexible crystals. This perspective summarizes elastic standards, plastic bending mechanisms, characterization methods, and potential development directions.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Materials Science, Ceramics
Mami Tanabe, Junichi Tatami, Motoyuki Iijima, Tsukaho Yahagi, Takuma Takahashi, Hiromi Nakano, Tatsuki Ohji
Summary: The yield stress and fracture strength of beta-Si3N4 single crystals were measured by bending tests of microcantilever beam specimens. The yield stress depended on the crystal orientation, and the plastic deformation resulted from dislocations in the primary slip system {101 over bar 0}$\{ 10\bar{1}0\} $. The fracture strength ranged approximately up to 20 GPa, depending on the crystal orientation, and the fracture behavior was discussed in terms of the accumulation of dislocations.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
Baptiste Bienvenu, Emmanuel Clouet
Summary: In this study, slip activity in body-centered cubic chromium was modeled by calculating the core properties and Peierls potential of screw dislocations using ab initio methods. It was found that screw dislocations with different Burgers vectors have different activation capabilities in various crystal orientations, and a broad range of crystal orientations was identified.
Article
Geochemistry & Geophysics
Joshua H. F. L. Davies, Richard A. Stern, Larry M. Heaman, Xavier Rojas, Erin L. Walton
AMERICAN MINERALOGIST
(2015)
Article
Optics
M. H. Bitarafan, H. Ramp, T. W. Allen, C. Potts, X. Rojas, A. J. R. MacDonald, J. P. Davis, R. G. DeCorby
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2015)
Article
Materials Science, Multidisciplinary
X. Rojas, J. P. Davis
Article
Instruments & Instrumentation
A. J. R. MacDonald, G. G. Popowich, B. D. Hauer, P. H. Kim, A. Fredrick, X. Rojas, P. Doolin, J. P. Davis
REVIEW OF SCIENTIFIC INSTRUMENTS
(2015)
Article
Geosciences, Multidisciplinary
Jesse R. Reimink, Joshua H. F. L. Davies, John W. F. Waldron, Xavier Rojas
JOURNAL OF THE GEOLOGICAL SOCIETY
(2016)
Article
Multidisciplinary Sciences
N. Zhelev, T. S. Abhilash, E. N. Smith, R. G. Bennett, X. Rojas, L. Levitin, J. Saunders, J. M. Parpia
NATURE COMMUNICATIONS
(2017)
Article
Physics, Applied
F. Souris, X. Rojas, P. H. Kim, J. P. Davis
PHYSICAL REVIEW APPLIED
(2017)
Article
Instruments & Instrumentation
N. Zhelev, T. S. Abhilash, R. G. Bennett, E. N. Smith, B. Ilic, J. M. Parpia, L. V. Levitin, X. Rojas, A. Casey, J. Saunders
REVIEW OF SCIENTIFIC INSTRUMENTS
(2018)
Article
Chemistry, Multidisciplinary
T. S. Biswas, Jin Xu, X. Rojas, C. Doolin, A. Suhel, K. S. D. Beach, J. P. Davis
Editorial Material
Physics, Multidisciplinary
Lev V. Levitin, Xavier Rojas, Petri J. Heikkinen, Andrew J. Casey, Jeevak M. Parpia, John Saunders
PHYSICAL REVIEW LETTERS
(2020)
Article
Multidisciplinary Sciences
P. J. Heikkinen, A. Casey, L. V. Levitin, X. Rojas, A. Vorontsov, P. Sharma, N. Zhelev, J. M. Parpia, J. Saunders
Summary: The research on surface Andreev bound states in superfluid He-3 demonstrates that they are fragile with respect to the details of surface scattering, unlike the robust surface/edge states in topological insulators and quantum Hall systems. The unexpectedly large suppression of T-c due to surface magnetic scattering leads to an increased density of low energy bound states.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Applied
S. Spence, Z. X. Koong, S. A. R. Horsley, X. Rojas
Summary: In the field of quantum optomechanics, superfluid 4He has been proposed as a promising mechanical element due to its highly desirable properties. However, current implementations suffer from external sources of loss. This study proposes an alternate implementation using nanofluidic confinement to limit radiation losses and preserve the intrinsic properties of superfluid 4He.
PHYSICAL REVIEW APPLIED
(2021)
Article
Physics, Applied
Sumit Kumar, Sebastian Spence, Simon Perrett, Zaynab Tahir, Angadjit Singh, Chichi Qi, Sara Perez Vizan, Xavier Rojas
Summary: We have developed a novel architecture for microwave cavity optomechanics at room temperature, using a 3D microwave re-entrant cavity and a compliant membrane. By resolving the thermomechanical motion of the membrane, we observed optomechanically induced transparency/absorption for the first time in a microwave optomechanical system operated at room temperature. Single-photon coupling rate (g0) was extracted through four independent measurement techniques, providing a full characterization of the proposed cavity optomechanical system.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Optics
A. J. R. MacDonald, B. D. Hauer, X. Rojas, P. H. Kim, G. G. Popowich, J. P. Davis