Dye-Zone A. Chen, Gang Chen^*

Frontiers in Heat and Mass Transfer, Vol.1, No.2, pp. 1-6, 2010, DOI:10.5098/hmt.v1.2.3005

Abstract We present a calculation of the thermally generated electromagnetic flux propagating along the in-plane direction of a polar, thin film. The approach is based on fluctuational electrodynamics and the fluctuation-dissipation theorem. We find that for silicon carbide films between 5 nm and 100 nm thick, the thinner films transport more in-plane flux due to the long propagation length of the anti-symmetric surface phonon-polariton mode. Comparison of results obtained from the fluctuation-dissipation approach and the kinetic theory approach shows favorable agreement. More >

Zhaohe Dai^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.09223

Abstract The flexible and clinging nature of ultra-thin films require the understanding of their elastic and adhesive properties in a wide range of circumstances from fabrications to applications. Simultaneously measuring both properties, however, is extremely difficult as the film thickness diminishes to nanoscales. In this talk, I will show our recent work that addresses such difficulties through peeling by vertically pulling thin films off from the substrates (we thus refer to it as “pull-to-peel”). Particularly, we perform in-situ pull-to-peel of graphene and MoS2 films in a scanning electron microscope and achieve simultaneous determination of their Young’s moduli and adhesions to gold… More >

Hongxing Shang^1,*, Xu Liang¹, Shengping Shen¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.09816

Abstract Flexoelectricity is the coupling effect of polarization and strain gradients, which tends to be more pronounced in thin films owing to size dependency. When subjected to in-plane compression, a filmsubstrate system will form complex wrinkle morphologies along with large-area and tunable strain gradients. The wrinkle-induced strain gradients can locally break the inversion symmetry of dielectrics and thus introduce flexoelectric polarization. Here, an electromechanical coupling model is developed to theoretically deal with flexoelectric polar patterns in wrinkled thin films. By analyzing the energy competition of elastic potential and electrostatic energy, the amplitude, wavelength, and critical strain of the wrinkles with flexoelectricity… More >

Yifan Xia, Jie Wang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.3, pp. 87-88, 2011, DOI:10.3970/icces.2011.020.087

Abstract Phase field simulation is an effective way to predict the domain evolution in ferroelectric materials. A phase field model is developed to investigate the domain structures and polarization switching in in ferroelectric thin films with deadlayers. Simulation results show that the deadlayers as well as misfit strain have a significant influence on the domain structures and polarization switching in the ferroelectric thin films. It is found that the simulated switching electric field in ferroelectric thin films decreases with the thickness of the deadlayers increasing. More >

Christophe Olivier^1,2, Jean Bruno Mougel^1,2, Patricia Bertoncini¹, Celine Moreau², Isabelle Capron², Bernard Cathala², Olivier Chauvet^1*

Journal of Renewable Materials, Vol.6, No.3, pp. 237-241, 2018, DOI:10.7569/JRM.2017.634168

Abstract Cellulose nanocrystals (CNCs) have a high ability to disperse single-walled carbon nanotubes (SWNTs) in aqueous media and to form hybrids. These hybrids are used to grow layer-by-layer thin films of controlled thickness. Thanks to the presence of SWNTs, these films are conducting. In this article, we describe the process by which the CNC/SWNT hybrids are obtained and discuss the electrical properties of the hybrid-based layer-by-layer films. More >

Chang-Chun Lee^1,*, Pei-Chen Huang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.2, pp. 239-260, 2019, DOI:10.32604/cmes.2019.06859

Abstract This research reviews the application of computational mechanics on the properties of nano/micro scaled thin films, in which the application of different computational methods is included. The concept and fundamental theories of concerned applications, material behavior estimations, interfacial delamination behavior, strain engineering, and multilevel modeling are thoroughly discussed. Moreover, an example of an interfacial adhesion estimation is presented to systematically estimate the related mechanical reliability issue in the microelectronic industry. The presented results show that the peeled mode fracture is the dominant delamination behavior of layered material system, with high stiffness along the bonding interface. However, the shear mode fracture… More >

P.H. Gaskell¹, Y.C. Lee², H.M. Thompson¹

CMES-Computer Modeling in Engineering & Sciences, Vol.62, No.1, pp. 77-112, 2010, DOI:10.3970/cmes.2010.062.077

Abstract The three-dimensional flow of a gravity-driven continuous thin liquid film on substrates containing micro-scale features is modelled using the long-wave lubrication approximation, encompassing cases when surface topography is either engulfed by the film or extends all the way though it. The discrete analogue of the time-dependent governing equations is solved accurately using a purpose designed multigrid strategy incorporating both automatic error-controlled adaptive time stepping and local mesh refinement/de-refinement. Central to the overall approach is a Newton globally convergent algorithm which greatly simplifies the inclusion of further physics via the solution of additional equations of the same form as the base… More >

Tai-Ming Chang¹, Chien-Chou Weng¹, Mei-Jiau Huang^1,2, Chun-KaiLiu², Chih-Kuang Yu²

CMES-Computer Modeling in Engineering & Sciences, Vol.50, No.1, pp. 47-66, 2009, DOI:10.3970/cmes.2009.050.047

Abstract We employ the non-equilibrium molecular dynamics (NEMD) simulation to calculate the in-plane thermal conductivity of silicon thin films of thickness 2.2nm and 11nm. To eliminate the finite-size effect, samples of various lengths are simulated and an extrapolation technique is applied. To perform the quantum correction which is necessary as the MD simulation temperature is lower than Debye temperature, the confined phonon spectra are obtained in advance via the EMD simulations. The investigation shows the thermal conductivities corrected based on the bulk and thin-film phonon densities of states are very close and they agree excellently with the theoretical predictions of a… More >

Arun K. Nair¹, Diana Farkas², Ronald D. Kriz¹

CMES-Computer Modeling in Engineering & Sciences, Vol.24, No.2&3, pp. 239-248, 2008, DOI:10.3970/cmes.2008.024.239

Abstract The indentation response of Ni thin films of thicknesses in the nano scale was studied using molecular dynamics simulations with embedded atom method (EAM) interatomic potentials. Simulations were performed in single crystal films in the [111] orientation with thicknesses of 7nm and 33nm. In the elastic regime, the loading curves observed start deviating from the Hertzian predictions for indentation depths greater than 2.5% of the film thickness. The observed loading curves are therefore dependent on the film thickness. The simulation results also show that the contact stress necessary to emit the first dislocation under the indenter is nearly independent of… More >

W. C. Liu, S. Q. Shi, C. H. Woo, Hanchen Huang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.2, pp. 213-218, 2002, DOI:10.3970/cmes.2002.003.213

Abstract Using molecular dynamics method, we study the nucleation of dislocations and their subsequent propagation during the deposition of tungsten thin films under tension. Aiming to reveal the generic mechanisms of dislocation nucleation during the deposition of polycrystalline thin films, the case of tungsten on a substrate of the same material is considered. The substrate is under uniaxial tension along the [111] direction, with the thermodynamically favored (01^ˉˉ1) surface being horizontal. The simulation results indicate that the nucleation starts with a surface step, where a surface atom is pressed into the film along the [111^ˉˉ] direction. This process leads… More >