Tags

Type your tag names separated by a space and hit enter

Impact of screw and edge dislocations on the thermal conductivity of individual nanowires and bulk GaN: a molecular dynamics study.
Phys Chem Chem Phys 2018; 20(7):5159-5172PC

Abstract

We report the thermal transport properties of wurtzite GaN in the presence of dislocations using molecular dynamics simulations. A variety of isolated dislocations in a nanowire configuration are analyzed and found to considerably reduce the thermal conductivity while impacting its temperature dependence in a different manner. Isolated screw dislocations reduce the thermal conductivity by a factor of two, while the influence of edge dislocations is less pronounced. The relative reduction of thermal conductivity is correlated with the strain energy of each of the five studied types of dislocations and the nature of the bonds around the dislocation core. The temperature dependence of the thermal conductivity follows a physical law described by a T-1 variation in combination with an exponent factor that depends on the material's nature, type and the structural characteristics of the dislocation core. Furthermore, the impact of the dislocation density on the thermal conductivity of bulk GaN is examined. The variation and absolute values of the total thermal conductivity as a function of the dislocation density are similar for defected systems with both screw and edge dislocations. Nevertheless, we reveal that the thermal conductivity tensors along the parallel and perpendicular directions to the dislocation lines are different. The discrepancy of the anisotropy of the thermal conductivity grows with increasing density of dislocations and it is more pronounced for the systems with edge dislocations. Besides the fundamental insights of the presented results, these could also be used for the identification of the type of dislocations when one experimentally obtains the evolution of thermal conductivity with temperature since each type of dislocation has a different signature, or one could extract the density of dislocations with a simple measurement of thermal anisotropy.

Authors+Show Affiliations

CNRS, CETHIL, UMR 5008, 69100 Villeurbanne, France. konstantinos.termentzidis@insa-lyon.fr.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

29393935

Citation

Termentzidis, Konstantinos, et al. "Impact of Screw and Edge Dislocations On the Thermal Conductivity of Individual Nanowires and Bulk GaN: a Molecular Dynamics Study." Physical Chemistry Chemical Physics : PCCP, vol. 20, no. 7, 2018, pp. 5159-5172.
Termentzidis K, Isaiev M, Salnikova A, et al. Impact of screw and edge dislocations on the thermal conductivity of individual nanowires and bulk GaN: a molecular dynamics study. Phys Chem Chem Phys. 2018;20(7):5159-5172.
Termentzidis, K., Isaiev, M., Salnikova, A., Belabbas, I., Lacroix, D., & Kioseoglou, J. (2018). Impact of screw and edge dislocations on the thermal conductivity of individual nanowires and bulk GaN: a molecular dynamics study. Physical Chemistry Chemical Physics : PCCP, 20(7), pp. 5159-5172. doi:10.1039/c7cp07821h.
Termentzidis K, et al. Impact of Screw and Edge Dislocations On the Thermal Conductivity of Individual Nanowires and Bulk GaN: a Molecular Dynamics Study. Phys Chem Chem Phys. 2018 Feb 14;20(7):5159-5172. PubMed PMID: 29393935.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Impact of screw and edge dislocations on the thermal conductivity of individual nanowires and bulk GaN: a molecular dynamics study. AU - Termentzidis,Konstantinos, AU - Isaiev,Mykola, AU - Salnikova,Anastasiia, AU - Belabbas,Imad, AU - Lacroix,David, AU - Kioseoglou,Joseph, PY - 2018/2/3/pubmed PY - 2018/2/3/medline PY - 2018/2/3/entrez SP - 5159 EP - 5172 JF - Physical chemistry chemical physics : PCCP JO - Phys Chem Chem Phys VL - 20 IS - 7 N2 - We report the thermal transport properties of wurtzite GaN in the presence of dislocations using molecular dynamics simulations. A variety of isolated dislocations in a nanowire configuration are analyzed and found to considerably reduce the thermal conductivity while impacting its temperature dependence in a different manner. Isolated screw dislocations reduce the thermal conductivity by a factor of two, while the influence of edge dislocations is less pronounced. The relative reduction of thermal conductivity is correlated with the strain energy of each of the five studied types of dislocations and the nature of the bonds around the dislocation core. The temperature dependence of the thermal conductivity follows a physical law described by a T-1 variation in combination with an exponent factor that depends on the material's nature, type and the structural characteristics of the dislocation core. Furthermore, the impact of the dislocation density on the thermal conductivity of bulk GaN is examined. The variation and absolute values of the total thermal conductivity as a function of the dislocation density are similar for defected systems with both screw and edge dislocations. Nevertheless, we reveal that the thermal conductivity tensors along the parallel and perpendicular directions to the dislocation lines are different. The discrepancy of the anisotropy of the thermal conductivity grows with increasing density of dislocations and it is more pronounced for the systems with edge dislocations. Besides the fundamental insights of the presented results, these could also be used for the identification of the type of dislocations when one experimentally obtains the evolution of thermal conductivity with temperature since each type of dislocation has a different signature, or one could extract the density of dislocations with a simple measurement of thermal anisotropy. SN - 1463-9084 UR - https://www.unboundmedicine.com/medline/citation/29393935/Impact_of_screw_and_edge_dislocations_on_the_thermal_conductivity_of_individual_nanowires_and_bulk_GaN:_a_molecular_dynamics_study_ L2 - https://doi.org/10.1039/c7cp07821h DB - PRIME DP - Unbound Medicine ER -