Impact of Grain Boundaries on the Heat Conductivity of Mono-Layer Hexagonal Boron Nitride

2017 ◽  
Author(s):  
Mohan S. R. Elapolu ◽  
Alireza Tabarraei
Keyword(s):  
Boron Nitride ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Temperature Profile ◽  
Misorientation Angle ◽  
Hexagonal Boron Nitride ◽  
Orientation Angle ◽  
Nonequilibrium Molecular Dynamics ◽  
Mono Layer ◽  
Kapitza Conductance

Reverse nonequilibrium molecular dynamics modeling is used to study the influence of grain boundaries on thermal properties of mono–layer hexagonal boron nitride (h–BN) nanoribbons. We consider symmetric grain boundaries consisting of series of pentagon–heptagon ring defects. Our results show a jump in the temperature profile at the location of grain boundary. The jump is consistently increasing with increase in the mis-orientation angle of nanoribbons with grain boundaries. This is attributed to an increase in the pentagon–heptagon defect density along the grain boundary. The temperature profile is used to calculate the Kapitza (interface) conductance of grain boundaries as a function of the misorientation angle of grain boundaries. Our results show that Kapitza conductance of the grain boundaries decreases with increase in the misorientation angle. Zigzag nanoribbons show slightly higher Kapitza conductance than armchair nanoribbons.

scholarly journals Grain boundaries in chemical-vapor-deposited atomically thin hexagonal boron nitride

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Xibiao Ren ◽  
Jichen Dong ◽  
Peng Yang ◽  
Jidong Li ◽  
Guangyuan Lu ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Grain Boundaries ◽  
Hexagonal Boron Nitride ◽  
Chemical Vapor ◽  
Chemical Vapor Deposited

Grain Boundary and Misorientation Angle Dependent Thermal Transport in Single-layer MoS2

Nanoscale ◽  
2022 ◽  
Author(s):  
Ke Xu ◽  
Ting Liang ◽  
Zhisen Zhang ◽  
Xuezheng Cao ◽  
Meng Han ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Misorientation Angle ◽  
Thermal Transport ◽  
Single Layer ◽  
Large Area ◽  
Grain Misorientation

Grain boundaries (GBs) are inevitable defects in large-area MoS2 samples but play a key role in their properties, however, the influence of grain misorientation on thermal transport remains largely unknown...

Motion of Grain Boundaries: Experiments on Bicrystals

2015 ◽  
Vol 5 ◽  
pp. 247-271
Author(s):  
Dmitri A. Molodov
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Misorientation Angle ◽  
Elevated Temperatures ◽  
Activation Enthalpy ◽  
Boundary Migration ◽  
Boundary Energy ◽  
Boundary Plane ◽  
Migration Behavior ◽  
Twist Boundaries

Recent research on grain boundary migration is reviewed. Novel in-situ measuring techniques based on orientation contrast imaging and the experimental results obtained on specially grown bicrystals are presented. Particularly, the investigated faceting and migration behavior of low angle grain boundaries under the curvature force in aluminum bicrystals was addressed. In contrast to the pure tilt boundaries, which remained straight/flat and immobile during annealing at elevated temperatures, mixed tilt-twist boundaries readily assumed a curved shape and steadily moved under the capillary force. Computational analysis revealed that this behavior is due to the inclinational anisotropy of grain boundary energy, which in turn depends on boundary geometry. The migration of planar grain boundaries induced by a magnetic field was measured in bismuth and zinc bicrystals. Various structurally different boundaries were investigated. The results revealed that grain boundary mobility essentially depends on the misorientation angle and the inclination of the boundary plane. Stress driven boundary migration in aluminium bicrystals was observed to be coupled to a tangential translation of the grains. The activation enthalpy of high angle boundary migration was found to vary non-monotonously with misorientation angle, whereas for low angle boundaries the migration activation enthalpy was virtually the same. The motion of the mixed tilt-twist boundaries under stress was observed to be accompanied by both the translation of adjacent grains parallel to the boundary plane and their rotation around the boundary plane normal.

Observations of Interaction Between Magnetic Domain Wall and Grain Boundaries in Fe-3wt%Si Alloy by Kerr Microscopy

1999 ◽  
Vol 586 ◽  
Author(s):  
K. Kawahara ◽  
Y. Yagyu ◽  
S. Tsurekawa ◽  
T. Watanabe
Keyword(s):  
Domain Wall ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Domain Structure ◽  
Misorientation Angle ◽  
Magnetic Domain ◽  
Magnetic Domain Structure ◽  
Magnetic Domain Wall ◽  
Domain Structures ◽  
Grain Boundary Plane

ABSTRACTMagnetic domain structures in Fe-3wt%Si alloy have been observed by a Kerr microscopy to understand the interaction between the magnetic domain wall and grain boundaries. It was found that the domain structures in the vicinity of the grain boundary depend on the misorientation angle; the high angle random boundary disturbs the magnetic domain structure more than the low angle boundary. In addition to the misorientation angle, magnetic domain structures were affected by the inclination of the grain boundary plane. Moreover, dynamic observations of rearrangement of the magnetic domain structure during magnetization revealed that grain boundaries could act as the sink and/or the source for magnetic domains.

scholarly journals Secondary Recrystallization Goss Texture Development in a Binary Fe81Ga19 Sheet Induced by Inherent Grain Boundary Mobility

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1254
Author(s):  
Zhenghua He ◽  
Yuhui Sha ◽  
Ning Shan ◽  
Yongkuang Gao ◽  
Fan Lei ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Grain Growth ◽  
Misorientation Angle ◽  
Secondary Recrystallization ◽  
Angle Distribution ◽  
Boundary Mobility ◽  
Goss Texture ◽  
Grain Boundary Mobility ◽  
Misorientation Angle Distribution

Secondary recrystallization Goss texture was efficiently achieved in rolled, binary Fe81Ga19 alloy sheets without the traditional dependence on inhibitors and the surface energy effect. The development of abnormal grain growth (AGG) of Goss grains was analyzed by quasi-situ electron backscatter diffraction (EBSD). The special primary recrystallization texture with strong {112}–{111}<110> and weak Goss texture provides the inherent pinning effect for normal grain growth by a large number of low angle grain boundaries (<15°) and very high angle grain boundaries (>45°) according to the calculation of misorientation angle distribution. The evolution of grain orientation and grain boundary characteristic indicates that the higher fraction of high energy grain boundaries (20–45°) around primary Goss grains supplies a relative advantage in grain boundary mobility from 950 °C to 1000 °C. The secondary recrystallization in binary Fe81Ga19 alloy is realized in terms of the controllable grain boundary mobility difference between Goss and matrix grains, coupled with the orientation and misorientation angle distribution of adjacent matrix grains.

scholarly journals Thermal Conductance along Hexagonal Boron Nitride and Graphene Grain Boundaries

Energies ◽  
2018 ◽  
Vol 11 (6) ◽  
pp. 1553 ◽  
Author(s):  
Timon Rabczuk ◽  
Mohammad Azadi Kakavand ◽  
Raahul Palanivel Uma ◽  
Ali Hossein Nezhad Shirazi ◽  
Meysam Makaremi
Keyword(s):  
Boron Nitride ◽  
Grain Boundaries ◽  
Hexagonal Boron Nitride ◽  
Thermal Conductance
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