Carbon Nanotube Array Thermal Interfaces on Chemical Vapor Deposited Diamond

2007 ◽  
Author(s):  
Baratunde A. Cola ◽  
Xianfan Xu ◽  
Timothy S. Fisher
Keyword(s):  
Carbon Nanotube ◽  
Diamond Film ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Photoacoustic Technique ◽  
Nanotube Array ◽  
Carbon Nanotube Array ◽  
Chemical Vapor Deposited ◽  
Cnt Arrays ◽  
Film Interface

Carbon nanotube (CNT) arrays have been directly synthesized on plasma-enhanced chemical vapor deposited diamond films in the same growth chamber. The diamond films were grown using a bias-enhanced nucleation technique that produces relatively smooth and flat films. The thermal resistances of the CNT array/diamond film interface were measured using a photoacoustic technique to be approximately 12 mm2·K/W at moderate pressures.

scholarly journals Synthesis of High-Quality Carbon Nanotube Arrays without the Assistance of Water

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Yongfeng Luo ◽  
Xinjun Wang ◽  
Mengdong He ◽  
Xi Li ◽  
Hong Chen
Keyword(s):  
Carbon Nanotube ◽  
Carbon Source ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Nanotube Arrays ◽  
High Quality ◽  
Nanotube Array ◽  
Carbon Nanotube Arrays ◽  
Cnt Arrays ◽  
First Time

Long and high-quality carbon nanotube (CNT) arrays have been synthesized through a chemical vapor deposition process. The Fe/Al2O3on silicon was used as the catalyst, ethylene as the carbon source, and a gas mixture of Ar and H2gases as the carrying gas. It is found for the first time that the high-quality and superlong carbon nanotube array can be improved by varying the content of hydrogen and carbon source.

Preparation of Nanocrystalline Diamond Films on Molybdenum Substrate by Double Bias Method

2006 ◽  
Vol 315-316 ◽  
pp. 646-650 ◽  
Author(s):  
Feng Xu ◽  
Dun Wen Zuo ◽  
Wen Zhuang Lu ◽  
Xiang Feng Li ◽  
Bing Kun Xiang ◽  
...  
Keyword(s):  
Bias Voltage ◽  
Diamond Film ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Nucleation Density ◽  
Nanocrystalline Diamond Films ◽  
Chemical Vapor Deposited ◽  
Hot Filament ◽  
Polycrystalline Molybdenum

The synthesis of nanocrystalline diamond film on polycrystalline molybdenum substrates was carried out by using of self-made hot filament chemical vapor deposited (HFCVD) system. Positive bias voltage on the grid electrode on top of hot filaments and negative bias voltage on the substrate were applied. High purity and extremely smooth nanocrystalline diamond films were successfully prepared by using the double bias method. Raman, SEM, XRD and AFM results show that the diamond films obtained have grain sizes less than 20nm, nucleation density higher than 1011cm-1. The mechanism of double bias is also discussed in this paper. The positive grid bias increases the active, decomposition and ionization of hydrogen and methane molecules, while negative substrate bias helps positive carbon-containing ions bombard the substrate that leads to the high nucleation density of the diamond film.

Carbon Nanotube Array Thermal Interfaces Enhanced With Paraffin Wax

2008 ◽  
Author(s):  
Baratunde A. Cola ◽  
Stephen L. Hodson ◽  
Xianfan Xu ◽  
Timothy S. Fisher
Keyword(s):  
Carbon Nanotube ◽  
Paraffin Wax ◽  
Nanotube Array ◽  
Carbon Nanotube Array ◽  
Real Contact ◽  
Cnt Arrays ◽  
Sample Structure ◽  
Individual Cnts ◽  
Thermal Interfaces ◽  
Wax Coating

Vertically oriented carbon nanotube (CNT) arrays can increase real contact in thermal interfaces and efficiently transfer heat between the mating solids. In this study, a paraffin wax that changes phase at approximately 50°C was applied to interfaces with CNT arrays directly synthesized on one side of the interface, and to foil/CNT interfaces with CNT arrays directly synthesized on one side and both sides of the foil. The bulk thermal resistances of single-sided CNT array/wax interfaces were measured using a transient photoacoustic (PA) technique to range from approximately 2 to 3 mm2·K/W under moderate pressures. The bulk thermal resistances of foil/CNT/wax interfaces were measured with the PA technique to range from approximately 10 to 20 mm2·K/W under moderate pressures. For each sample structure, the addition of paraffin wax to the CNT arrays produced significant reductions in thermal resistance. We surmise that this improved thermal performance could be a function of the wettability of paraffin wax to CNTs. A hydrophilic wetting angle of approximately 47° was observed at the interface of liquid wax and the free tips of a CNT array at 60°C, and field-emission scanning electron microscope images taken after PA testing revealed individual CNTs that were blanketed with a wax coating.

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