The effect of UV and thermally induced oxidation on the surface and structural properties of CVD diamond layers with different grain sizes

Extensive Raman spectroscopy studies combined with scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) measurements were performed to investigate structural and chemical changes in diamond layers deposited by chemical vapour deposition (CVD) upon post-growth treatment with hydrogen. The aim of this study is to characterize the changes in micro-structural properties of diamond layers with different grain sizes and different contents of sp2 carbon phase. Hydrogenation or oxidization of diamond layer surface is often performed to modify its properties; however, it can also strongly affect the surface structure. In this study, the impact of hydrogenation on the structure of diamond layer surface and its chemical composition is investigated. Owing to their polycrystalline nature, the structural properties of CVD diamond layers can strongly differ within the same layer. Therefore, in this project, in order to compare the results before and after hydrogen treatment, the diamond layers are subjected to Raman spectroscopy studies in the vicinity of a T-shape marker fabricated on the surface of each diamond layer studied.

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Optical, electrical, and structural properties of amorphous Ag–Ge–S and Ag–Ge–Se films and comparison of photoinduced and thermally induced phenomena of both systems

Journal of Applied Physics ◽

10.1063/1.362644 ◽

1996 ◽

Vol 79 (12) ◽

pp. 9096-9104 ◽

Cited By ~ 70

Author(s):

Takeshi Kawaguchi ◽

Shigeo Maruno ◽

Stephen R. Elliott

Keyword(s):

Structural Properties ◽

Thermally Induced

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Effect of Low-Temperature Aging on Thermally-Induced Phase Transformation of NiTi Wire with a Wide Range of Grain Sizes

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1042.9 ◽

2021 ◽

Vol 1042 ◽

pp. 9-16

Author(s):

Zhi Hao Zhao ◽

Jian Ping Lin ◽

Jun Ying Min ◽

Yong Hou ◽

Bo Sun

Keyword(s):

Grain Size ◽

Phase Transformation ◽

Low Temperature ◽

Thermally Induced ◽

Grain Sizes ◽

Average Grain Size ◽

Wide Range ◽

Low Temperature Aging ◽

Niti Wires ◽

Temperature Aging

Thermally-induced phase transformation (PT) is of significance and value to the application of NiTi alloy components. Low-temperature aging (LTA) treatment was used to alter PT characteristics of NiTi alloys avoiding undesirable grain growth. Effect of LTA on PT of NiTi wires with a wide range of grain sizes from 34 nm to 8021 nm was investigated in this study. As the average grain size varies from 34 to 217 nm, the temperature of the B2↔R transformation increase as a result of LTA, and the increasing effect is more obvious at a larger grain size. For NiTi alloys with average grain sizes ranging from 523 to 1106 nm, transformation sequence changes from B2↔B19' to B2↔R due to LTA. For the sample with an average grain size of 2190 nm, the B2↔B19' transformation is replaced by B2↔R←B19' after LTA. When the average grain size is larger than 2190 nm, transformation sequence changes from B2↔B19' to B2↔R↔B19' after LTA. Transmission emission microscope observations reveal that the above-mentioned PT behavior correlates with the coupled effect of grain size and precipitation. The precipitation of Ni4Ti3 in the grains with a size smaller than ~150 nm is inhibited after LTA, the temperature of B2→R of samples with average GS smaller than ~150 nm still is elevated due to the inhomogeneous grain size of NiTi wires.

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Correlation between breakdown voltage and structural properties of polycrystalline and heteroepitaxial CVD diamond films

Diamond and Related Materials ◽

10.1016/0925-9635(94)90307-7 ◽

1994 ◽

Vol 3 (4-6) ◽

pp. 951-956 ◽

Cited By ~ 18

Author(s):

R. Hessmer ◽

M. Schreck ◽

S. Geier ◽

B. Stritzker

Keyword(s):

Structural Properties ◽

Breakdown Voltage ◽

Diamond Films ◽

Cvd Diamond

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A new method to determine open porosity and permeability constants of open-pore sintered glasses by photoacoustic technique

Cerâmica ◽

10.1590/s0366-69132005000300013 ◽

2005 ◽

Vol 51 (319) ◽

pp. 259-264

Author(s):

M. T. Yasuda ◽

W. L. B. Melo

Keyword(s):

Structural Properties ◽

Open Porosity ◽

Porous Ceramic ◽

Photoacoustic Signal ◽

Photoacoustic Technique ◽

Excellent Correlation ◽

Grain Sizes ◽

Porosity And Permeability ◽

Permeability Constants ◽

Non Destructive

The Photoacoustic (PA) technique was used to investigate the structural properties (e.g. open porosity and permeability) of open-pore sintered glasses. This work demonstrates that the photoacoustic signal of open-pore sintered glasses, which are produced with different grain sizes and several degrees of open porosity, is sensitive to the morphology of the open-pore samples. The results obtained by the PA technique were related to results obtained by the Pressure Decay technique, and an excellent correlation was obtained. This demonstrates that PA technique, which is non-intrusive and non-destructive, is promising for application in analysis of porous ceramic structures, even if the sample is semi-transparent.

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