scholarly journals Temperature dependent thermal conductivity of pure silica MEL and MFI zeolite thin films

2012 ◽  
Vol 111 (5) ◽  
pp. 054910 ◽  
Author(s):  
Jin Fang ◽  
Yi Huang ◽  
Christopher M. Lew ◽  
Yushan Yan ◽  
Laurent Pilon
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Mfi Zeolite ◽  
Temperature Dependent ◽  
Pure Silica ◽  
Temperature Dependent Thermal Conductivity

scholarly journals Temperature Dependent Thermal Conductivity of Pure Silica MEL and MFI Zeolite Thin Films

2012 ◽  
Author(s):  
Jin Fang ◽  
Yi Huang ◽  
Laurent Pilon ◽  
Christopher M. Lew ◽  
Yushan Yan
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Conductivity ◽  
Surface Area ◽  
Silica Matrix ◽  
Simultaneous Increase ◽  
Mfi Zeolite ◽  
Temperature Dependent ◽  
Relative Crystallinity ◽  
Pure Silica

This paper reports the temperature dependent cross-plane thermal conductivity of pure silica zeolite (PSZ) MEL and MFI thin films between 30 and 315 K. PSZ MFI thin films were made by in situ crystallization. They were b-oriented, fully crystalline and had a 33% porosity. PSZ MEL thin films were prepared by spin coating a suspension of MEL nanoparticles in 1-butanol solution onto silicon substrates followed by calcination and vapor-phase silylation with trimethylchlorosilane. The MEL films consisted of MEL nanoparticles embedded in a non-uniform and highly porous silica matrix. They featured porosity, relative crystallinity, and MEL nanoparticles size ranging from 40% to 59%, 23% to 47% and 55 to 80 nm, respectively. The cross-plane thermal conductivity of these PSZ thin films was measured using the 3ω method. Although the PSZ MFI thin film was fully crystalline and had smaller porosity than the MEL films, it was found to have thermal conductivity only slightly larger than that of MEL thin films for all temperatures. This was due to the fact that the MFI thin film had large microporosity and micropore surface area. This, in turn, greatly enhanced phonon-pore scattering and reduced thermal conductivity. In addition, for PSZ MEL films, the effect of increases in the relative crystallinity and nanoparticle size on the thermal conductivity was compensated by the simultaneous increase in porosity. Finally, all measured thermal conductivity was linearly proportional to Tn with n varying from 2 to 2.6 for temperature T < 60 K. This can be attributed to the fact that the PSZ thin films featured crystalline nanostructures which were highly disordered due to the large surface area of pores and nanocrystals.

scholarly journals Thermal conductivity of pure silica MEL and MFI zeolite thin films

2010 ◽  
Vol 108 (4) ◽  
pp. 044902 ◽  
Author(s):  
Thomas Coquil ◽  
Christopher M. Lew ◽  
Yushan Yan ◽  
Laurent Pilon
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Mfi Zeolite ◽  
Pure Silica

Cross-plane temperature-dependent thermal conductivity of Al-doped zinc oxide thin films

2015 ◽  
Vol 638 ◽  
pp. 83-87 ◽  
Author(s):  
Tae-Hyun Park ◽  
No-Won Park ◽  
Jinhwan Kim ◽  
Won-Yong Lee ◽  
Jung-Hyuk Koh ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Zinc Oxide ◽  
Oxide Thin Films ◽  
Temperature Dependent ◽  
Plane Temperature ◽  
Temperature Dependent Thermal Conductivity

scholarly journals Reduced temperature-dependent thermal conductivity of magnetite thin films by controlling film thickness

2014 ◽  
Vol 9 (1) ◽  
pp. 96 ◽  
Author(s):  
No-Won Park ◽  
Won-Yong Lee ◽  
Jin-A Kim ◽  
Kyungjun Song ◽  
Hyuneui Lim ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Film Thickness ◽  
Temperature Dependent ◽  
Reduced Temperature ◽  
Temperature Dependent Thermal Conductivity

scholarly journals Thermal Conductivity of Pure Silica MEL and MFI Zeolite Thin Films

2010 ◽  
Author(s):  
Thomas Coquil ◽  
Laurent Pilon ◽  
Christopher M. Lew ◽  
Yushan Yan
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Room Temperature ◽  
Sol Gel ◽  
Silica Matrix ◽  
Simultaneous Increase ◽  
Crystallization Time ◽  
Mfi Zeolite ◽  
Relative Crystallinity ◽  
Pure Silica

This paper reports the room temperature cross-plane thermal conductivity of pure silica zeolite (PSZ) MEL and MFI thin films. PSZ MEL thin films were prepared by spin coating a suspension of MEL nanoparticles in 1-butanol solution onto silicon substrates followed by calcination and vapor-phase silylation with trimethylchlorosilane. The mass fraction of nanoparticles within the suspension varied from 16 to 55%. This was achieved by varying the crystallization time of the suspension. The thin films consisted of crystalline MEL nanoparticles embedded in a non-uniform and highly porous silica matrix. They featured porosity, relative crystallinity and MEL nanoparticles size ranging from 40 to 59%, 23 to 47% and 55 to 80 nm, respectively. PSZ MFI thin films were made by in-situ crystallization, were b-oriented, fully crystalline and had a 33% porosity. Thermal conductivity of the PSZ thin films was measured at room temperature using the 3ω method. The cross-plane thermal conductivity of the MEL thin films remained constant around 1.02 ± 0.10 Wm−1K−1 despite increases in (i) relative crystallinity, (ii) nanoparticle size and (iii) yield as the nanoparticle crystallization time increased. Indeed, the effect of increases in these parameters on the thermal conductivity was compensated by the simultaneous increase in porosity. PSZ MFI thin films were found to have the same thermal conductivity as MEL thin films even though they had smaller porosity. Finally, the average thermal conductivity of the PSZ films was three to five times larger than that reported for amorphous sol-gel mesoporous silica thin films with similar porosity and dielectric constant.

Thermal Conductivity Anisotropy in Phonon Transport of Bi2Te3/Bi0.5Sb1.5Te3 Superlattice Film

2020 ◽  
Vol 15 (4) ◽  
pp. 463-467
Author(s):  
Soo-Young Kang ◽  
No-Won Park ◽  
Won-Yong Lee ◽  
Min-Sung Kang ◽  
Gil-Sung Kim ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Electron Scattering ◽  
Phonon Scattering ◽  
Phonon Transport ◽  
Temperature Dependent ◽  
Conductivity Anisotropy ◽  
Large Anisotropy ◽  
Temperature Dependent Thermal Conductivity ◽  
Thermal Conductivities

Nanoscale superlattice thin films generally exhibit larger phonon and electron scattering at the interface in the direction of the cross-plane of the samples. Therefore, it is very important to further detailed study of especially phonon transport of the superlattice films. Here, we report temperature dependent thermal conductivity anisotropy in phonon transport of Bi2 Te3 /Bi0.5 Sb1.5 Te3 superlattice thin films at 200–500 K. Thermal conductivity of these thin films for in- and cross-plane thermal conductivities were determined to be approximately 0.74 and 0.4 W m–1 K–1 at 200–500 K, respectively, clearly indicating ∼185% suppression in- and cross-plane thermal conductivities of the superlattice thin films with a large anisotropic behavior. Such large anisotropy in the thermal conductivity can be attributed to enhanced phonon scattering occurring at the interface of the Bi2Te3 and Bi0.5Sb1.5Te3 layer.

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