scholarly journals Doped Nanocrystalline Diamond Films as Reflective Layers for Fiber-Optic Sensors of Refractive Index of Liquids

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2124 ◽  
Author(s):  
Monika Kosowska ◽  
Daria Majchrowicz ◽  
Kamatchi J. Sankaran ◽  
Mateusz Ficek ◽  
Ken Haenen ◽  
...  
Keyword(s):  
Refractive Index ◽  
Fiber Optic ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Fiber Optic Sensors ◽  
Nanocrystalline Diamond ◽  
Silicon Substrates ◽  
Boron Doped ◽  
Interferometric Sensor

This paper reports the application of doped nanocrystalline diamond (NCD) films—nitrogen-doped NCD and boron-doped NCD—as reflective surfaces in an interferometric sensor of refractive index dedicated to the measurements of liquids. The sensor is constructed as a Fabry–Pérot interferometer, working in the reflective mode. The diamond films were deposited on silicon substrates by a microwave plasma enhanced chemical vapor deposition system. The measurements of refractive indices of liquids were carried out in the range of 1.3 to 1.6. The results of initial investigations show that doped NCD films can be successfully used in fiber-optic sensors of refractive index providing linear work characteristics. Their application can prolong the lifespan of the measurement head and open the way to measure biomedical samples and aggressive chemicals.

Study of Undoped Nanocrystalline Diamond Films Grown by Microwave Plasma-Assisted Chemical Vapor Deposition

2021 ◽  
Vol 55 (1) ◽  
pp. 66-75
Author(s):  
A. L. Vikharev ◽  
S. A. Bogdanov ◽  
N. M. Ovechkin ◽  
O. A. Ivanov ◽  
D. B. Radishev ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Nanocrystalline Diamond Films

A sequential Raman analysis of the growth of diamond films on silicon substrates in a microwave plasma assisted chemical vapor deposition reactor

1997 ◽  
Vol 12 (10) ◽  
pp. 2686-2698 ◽  
Author(s):  
L. Fayette ◽  
B. Marcus ◽  
M. Mermoux ◽  
N. Rosman ◽  
L. Abello ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Sequential Analysis ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Diamond Growth ◽  
Internal Stresses ◽  
Nucleation Density ◽  
Silicon Substrates

A sequential analysis of the growth of diamond films on silicon substrates in a microwave plasma assisted chemical vapor deposition (CVD) reactor has been performed by Raman spectroscopy. The plasma was switched off during measurements, but the substrate heating was maintained to minimize thermoelastic stresses. The detectivity of the present experimental setup has been estimated to be about a few tens of μmg/cm2. From such a technique, one expects to analyze different aspects of diamond growth on a non-diamond substrate. The evolution of the signals arising from the substrate shows that the scratching treatment used to increase the nucleation density induces an amorphization of the silicon surface. This surface is annealed during the first step of deposition. The evolution of the line shape of the spectra indicates that the non-diamond phases are mainly located in the grain boundaries. The variation of the integrated intensity of the Raman signals has been interpreted using a simple absorption model. A special emphasis was given to the evolution of internal stresses during deposition. It was verified that compressive stresses were generated when coalescence of crystals took place.

Thermal Stability of Nanocrystalline Diamond Films Grown by Microwave Plasma Chemical Vapor Deposition

2002 ◽  
Vol 750 ◽  
Author(s):  
Mevlut Bulut ◽  
Shane A. Catledge ◽  
Yogesh K. Vohra ◽  
Renato P. Camata
Keyword(s):  
Thermal Stability ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Plasma Chemical ◽  
Plasma Chemical Vapor Deposition ◽  
Nanocrystalline Diamond Films ◽  
Thermal Stability Of

ABSTRACTIn this work, the open-air thermal stability of nanocrystalline diamond films grown on mirror-polished titanium alloy substrates by the Microwave Plasma Chemical Vapor Deposition (MPCVD) technique was studied. The results of this investigation show that nanocrystalline diamond films are highly stable in air up to 600°C with no significant change in mechanical properties. Samples annealed between 600°C and 650°C, however, exhibit values of hardness lower by as much as 40% compared to as-grown samples. Above 650°C serious delamination effects were observed in the coatings.

MPACVD Nanocrystalline Diamond for Biomedical Applications

2007 ◽  
Vol 280-283 ◽  
pp. 1595-1598 ◽  
Author(s):  
Chuan Lin Zheng ◽  
Rong Qi ◽  
Wu Bao Yang
Keyword(s):  
Biomedical Applications ◽  
Microwave Plasma ◽  
Optical Glass ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Processing Parameters ◽  
Nanocrystalline Diamond ◽  
X Ray Diffraction ◽  
Nanocrystalline Diamond Films

In the present paper, nanocrystalline diamond films (NDFs) were fabricated on optical glass using microwave plasma assisted chemical vapor deposition (MPACVD). The suitable processing parameters are as followings: methane concentration 3% in argon, total deposition pressure 13.3 kPa, substrate temperature 500 °C. The diamond films were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy. In vitro osteoblast cell cultures and platelet adhesion tests were applied to evaluate the biocompatibility of the nanocrystalline diamond films (NDFs). All results indicate that the diamond films exhibit better tissue compatibility and hemocompatibility which are very suitable for biomedical applications.

DEPOSITION AND CHARACTERIZATION OF NANOCRYSTALLINE DIAMOND FILMS ON MIRROR-POLISHED Si SUBSTRATE BY BIASED ENHANCED MICROWAVE PLASMA CHEMICAL VAPOR DEPOSITION

2002 ◽  
Vol 16 (06n07) ◽  
pp. 845-852
Author(s):  
T. Soga ◽  
T. Sharda ◽  
T. Jimbo ◽  
M. Umeno
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Methane Concentration ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Silicon Substrates ◽  
Si Substrate ◽  
Plasma Chemical ◽  
Plasma Chemical Vapor Deposition

Hard and smooth nanocrystalline diamond (NCD) thin films were deposited on polished silicon substrates by biased enhanced growth in microwave plasma chemical vapor deposition. The films deposited with varying the methane concentration and biasing voltage were characterized by Raman spectroscopy, nano-indenter, x-ray diffraction and atomic force microscopy. Stress in the films increases with decreasing methane concentration in the gas-phase and with increasing biasing. The adhesion between NCD film and Si substrate is very strong sustaining the compressive stress as high as high as 85 GPa. It was hypothesized that hydrogen content of the films and graphitic content of the films are responsible in generating stress. The hardness is well correlated with the Raman peak intensity ratio of NCD peak to G peak.

Microcrystalline and Nanocrystalline Diamond Film Deposition on Cobalt Chrome Alloy

1999 ◽  
Vol 594 ◽  
Author(s):  
Marc D. Fries ◽  
Yogesh K. Vohra
Keyword(s):  
Diamond Film ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Film Deposition ◽  
Nanocrystalline Diamond ◽  
Plasma Chemical Vapor Deposition ◽  
High Thermal Expansion ◽  
Cobalt Chrome Alloy ◽  
Cobalt Chrome

AbstractThe cobalt chrome alloy Co-28Cr-6Mo is widely used in human joint replacement applications. These joints are highly sensitive to wear and are usually replaced after approximately ten years of use. In order to extend these implants' service lifetimes, a thin film of diamond may be applied to the implant wear surfaces by microwave plasma chemical vapor deposition (MPCVD) following MPCVD nitridation. Diamond films often delaminate from cobalt chrome due to a high thermal expansion mismatch. Additionally, under most conditions diamond films degrade into graphite by dissolution of nuclei into solvents like Co and Cr. By nitriding the cobalt chrome through MPCVD prior to diamond deposition, a usable diamond film may be achieved. It may be possible to merge both the nitriding and deposition steps into a single process, since both nitridation and deposition will be performed by MPCVD. In addition, controlled amounts of nitrogen in hydrogen/methane plasma under CVD conditions result in a nanostructured diamond coating. We have investigated the formation of both micro- and nanocrystalline diamond formation on cobalt chrome.

Determination of Boron Concentration in Doped Diamond Films

2011 ◽  
Vol 1282 ◽  
Author(s):  
S.N. Demlow ◽  
T.A. Grotjohn ◽  
T. Hogan ◽  
M. Becker ◽  
J. Asmussen
Keyword(s):  
Boron Concentration ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Boron Doped Diamond ◽  
Dopant Activation ◽  
Boron Doped ◽  
Boron Dopant ◽  
Boron Acceptor

ABSTRACTThe electrical characteristics of high quality single crystal boron-doped diamond are studied. Samples are synthesized in a high power-density microwave plasma-assisted chemical vapor deposition (CVD) reactor at a pressure of 160 Torr. The boron-doped diamond films are grown using diborane in the feedgas at concentrations of 0-0.25 ppm, and are compared to those grown previously with 1-10 ppm. The boron acceptor concentration is investigated using infrared absorption, and compared to the boron concentration obtained by SIMS. A four point probe is used to study the conductivity. The temperature dependent conductivity is analyzed to determine the boron dopant activation energy.

The Microstructure and Enhanced Field Electron Emission Properties of Boron-Doped Nanocrystalline Diamond Films by Microwave Plasma Chemical Vapor Deposition

2010 ◽  
Vol 152-153 ◽  
pp. 413-417
Author(s):  
You Sheng Zou ◽  
Zheng Xue Li ◽  
Hao Yang
Keyword(s):  
Electron Emission ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Field Electron Emission ◽  
Nanocrystalline Diamond ◽  
Gas Mixture ◽  
Emission Properties ◽  
Boron Doped ◽  
Field Electron ◽  
Nanocrystalline Diamond Films

The boron-doped nanocrystalline diamond films were prepared on Si(100) substrates by microwave plasma chemical vapor deposition in gas mixture of CH4/H2/trimethylboron (TMB) with B/C ratio in the range of 0-1900ppm. The dependencies of surface morphology, microstructure, phase composition and field electron emission properties on the B/C ratio were systematically investigated by scanning electron microscope, X-ray diffractometer, visible and UV Raman spectroscopy. The results show that the diamond grains gather together forming ball-like clusters with inhomogeneous size, the doped boron atoms can promote the growth of plane (111) surface and terminate the diamond growth sites, resulting in the reduction of growth rate with the increase of B/C ratio in the gas mixture. The two peaks located at approximately 500 and 1220cm-1 resulted from Fano interference were observed in the visible Raman spectra for the heavily boron-doped nanocrystalline diamond film, and the sp2/sp3 ratio of carbon bonds increased with B/C ratio increasing in gas mixture. The field electron emission performances of the boron-doped nanocrystalline diamond films were obviously dependent on B/C ratio in the gas mixture, and boron doping can improve their field electron emission properties remarkably. The low turn-on electric field of 7.6V/μm was achieved for the boron-doped nanocrystalline diamond film deposited at B/C ratio of 1900ppm.

Phase Transformation of Nanocrystalline Diamond Films: Effect of Methane Concentration

2020 ◽  
Vol 831 ◽  
pp. 127-131
Author(s):  
S.Tipawan Khlayboonme ◽  
Thowladda Warawoot
Keyword(s):  
Phase Transformation ◽  
Gas Phase ◽  
Electron Density ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Graphite Phase ◽  
Diamond Phase ◽  
Nanocrystalline Diamond Films

Ultra-nanocrystalline diamond films were prepared by a microwave plasma-enhanced chemical vapor deposition reactor using CH4/H2 gas mixture with a power as low as 650 W. The effects of CH4 concentration on nanostructure of the films and gas-phase species in plasma were investigated. The CH4 concentrations of 1.5%, 3.0%, 3.5%, and 4.0% were used and balanced with H2 to a total flow rate of 200 sccm. Morphology and composition of the films were characterized by SEM, Raman spectroscopy and Auger spectroscopy. The gas-phase species and electron density in the plasma were explored by optical emission spectroscopy and plasma-impedance measurement. The increasing CH4 concentration from 1.5% to 4.0% increased C2Hx species and decreased electron density. Phase of the film transform from nano- into ultranano- diamond phase but the growth rate revealingly decreased from 300 to 210 nm/h. Raman spectra indicate the higher CH4 concentration promted phase of the film transiton from NCD to UNCD. While Auger spectra revealed that UNCD film deposited with 4.0%CH4 was composed of 90.52% diamond phase but only 9.48% of graphite phase. The relation between phase transformation of the films and growth mechnism controlled by gas-phase species in the plasma will be dissused.

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