scholarly journals Low Deposition Temperature-Induced Changes of the Microstructure and Tribological Property of WS2 Film

Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 227 ◽  
Author(s):  
Ming Hu ◽  
Yi Dong ◽  
Yan Wang ◽  
Desheng Wang ◽  
Dong Jiang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Substrate Temperature ◽  
Tribological Properties ◽  
Room Temperature ◽  
Compact Structure ◽  
Radio Frequency Sputtering ◽  
Initial Substrate ◽  
Wear Life ◽  
Induced Changes ◽  
Deposited Film

Pure WS2 films were prepared by the radio frequency sputtering of a WS2 target with the initial substrate temperature controlled to −40, −25, 0 °C and room temperature by cooling the holder with liquid nitrogen, respectively. The influence of the substrate temperature on the microstructures and the tribological properties of the prepared films have been evaluated and the wear mechanism of the films was explained. It revealed that with decreasing the substrate temperature, the prepared WS2 film changed from the loose and coarse columnar plate structure for film deposited at room temperature to a much more compact morphology for film deposited at −40 °C. The WS2 film deposited at low temperature of −40 or −25 °C exhibited a long wear life higher than 5.0 × 105 sliding cycles, while this was about 1.5 × 105 cycles for the WS2 deposited at room temperature. The improved tribological properties for the low temperature-deposited film were mainly attributed to the much lower wear rate resulted from the compact structure as well as the sustained and steadily formed transform layer on the counterpart ball.

Deposition of Ti(C,N) Thick Films by ILPCVD Starting from TDMAT

1997 ◽  
Vol 495 ◽  
Author(s):  
S. Gilles ◽  
N. Bourhila ◽  
J. P. Senateur ◽  
R. Madar ◽  
R. A. Levy ◽  
...  
Keyword(s):  
Low Temperature ◽  
Substrate Temperature ◽  
Flow Rate ◽  
Growth Rates ◽  
Room Temperature ◽  
Injection Technique ◽  
Good Reproducibility ◽  
Fee Structure ◽  
Control Growth ◽  
Pulsed Injection

ABSTRACTTi(C,N) films have been deposited from tetrakis(dimethylamido)titanium (TDMAT) and ammonia by CVD at low pressure using pulsed Injection technique (ILPCVD). This procedure allows us to easily deposit Ti(C,N) films with a good reproducibility. It is an efficient technique to control growth rates and composition of coatings. The liquid TDMAT undergoes no degradation during deposition since it is kept at room temperature. Ti(C,N) films, with fee structure and fine grains were deposited at substrate temperature varying from 200 to 500 °C. Composition of films is controlled by substrate temperature and ammonia flow rate. Growth rates as high as 2 μm/min are reached for deposition of Ti(C,N) films at low temperature (350 °C).

scholarly journals Miniature All-Silica Microbubble-Based Fiber Optic Fabry-Perot Pressure Sensor with Pressure Leading-In Tube

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Huixin Zhang ◽  
Jia Liu ◽  
Jiashun Li ◽  
Pinggang Jia ◽  
Fei Feng ◽  
...  
Keyword(s):  
Low Temperature ◽  
Temperature Coefficient ◽  
Pressure Sensor ◽  
Room Temperature ◽  
Fiber Optic ◽  
Single Mode ◽  
External Pressure ◽  
Compact Structure ◽  
Fabry Perot ◽  
Length Changes

A novel all-silica fiber optic Fabry-Perot (FP) pressure sensor with pressure leading-in tube based on microbubble structure is developed and experimentally demonstrated. The FP cavity is formed by fixing the end face of the single-mode fiber (SMF) parallel to the outer surface of the microbubble, in which the microbubble with a diameter of about 318 μm is constructed at the end of silica hollow tube. When external pressure is transmitted on the inner surface of the microbubble by the pressure leading-in tube, the FP cavity length changes with the diameter of microbubble. Experimental results show that such a sensor has a linear sensitivity of approximately 4.84 nm/MPa at room temperature over the pressure range of 1.1 MPa; the sensor has a very low temperature coefficient of approximately 2 pm/°C from room temperature to 600°C. The sensor has advantages of extremely low temperature coefficient, compact structure, and small size, which has potential applications for measuring pressure in high-temperature environment.

The Effects of Substrate Temperature and Bias on the Structural, Mechanical and Tribological Properties of TiC films deposited by Magnetron Assisted Pulsed Laser Deposition

2001 ◽  
Vol 697 ◽  
Author(s):  
A.R. Phani ◽  
J.E. Krzanowski ◽  
J.J. Nainaparampil
Keyword(s):  
Substrate Temperature ◽  
Pulsed Laser Deposition ◽  
Tribological Properties ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Indentation Hardness ◽  
Substrate Bias ◽  
X Ray ◽  
Mechanical And Tribological Properties

AbstractTitanium carbide films have been deposited using a hybrid magnetron sputtering/ pulsed laser deposition technique. One set of films was deposited at substrate temperatures ranging from room temperature to 600oC with no substrate bias, and a second set was deposited at 400°C bias voltages up to -150V. X-ray diffraction, X-ray photoelectron spectroscopy, and electron microscopy were employed for structural and compositional characterization of the films, and nano-indentation hardness testing and pin-on-disc wear tests were used to evaluate the mechanical and tribological properties. All the TiC films deposited without substrate bias were highly crystalline. The films deposited with bias had significantly reduced crystallinity and non-stoichiometric film compositions. The hardness of the TiC films increased with substrate temperature from 8 GPa at room temperature to 18 GPa at 600oC, whereas the biased films had a maximum hardness of 12 GPa. The wear test data showed significantly lower friction and longer wear life for the -150V biased film.

Room temperature grain growth in sputtered Cu films

2002 ◽  
Vol 749 ◽  
Author(s):  
D. Deduytsche ◽  
C. Detavernier ◽  
J. Debaerdemaeker ◽  
R.L. Van Meirhaeghe ◽  
C. Dauwe ◽  
...  
Keyword(s):  
Substrate Temperature ◽  
Grain Growth ◽  
Room Temperature ◽  
Growth Zone ◽  
Cu Films ◽  
Deposition Parameters ◽  
Sputter Deposited ◽  
Zone Diagram ◽  
Kinetics Of ◽  
Deposited Film

ABSTRACTThe results are presented of a study on grain growth in magnetron sputter deposited Cu films. Similarly to the well-known case of electroplated Cu, we observed significant changes in the microstructure of sputter deposited films during storage at room temperature, as evidenced by a decrease in sheet resistance (up to 40% decrease in less than 6 hours). Direct evidence for grain growth was observed by FIB and SEM and by a strong decrease in the XRD peak width. Moreover, a decrease in the total defect content of the film was observed as a function of storage time from positron annihilation experiments, probably reflecting the decreasing number of grain boundaries in the film. It is well known that the microstructure of an as-deposited film is strongly dependent on the deposition parameters. This relationship is summarized in the Thornton structure-growth zone diagram [7]. We have studied the kinetics of room temperature grain growth as a function of Ar pressure and substrate temperature for Cu films with a thickness between 50 nm and 1 micrometer. It is found that spontaneous grain growth during storage at room temperature occurs mainly for a zone T microstructure (at low Ar pressure and a substrate temperature below 40°C), while it does not occur for zone I (high Ar pressure, low substrate temperature) or zone II (substrate temperature > 100°C) microstructures.

Survival of mouse blastocysts after low-temperature preservation under high pressure

2004 ◽  
Vol 52 (4) ◽  
pp. 479-487 ◽  
Author(s):  
Cs. Pribenszky ◽  
M. Molnár ◽  
S. Cseh ◽  
L. Solti
Keyword(s):  
Phase Transition ◽  
Hydrostatic Pressure ◽  
Low Temperature ◽  
High Hydrostatic Pressure ◽  
Room Temperature ◽  
Freezing Point ◽  
Significant Loss ◽  
Embryo Cryopreservation ◽  
Subzero Temperatures ◽  
Survival Capacity

Cryoinjuries are almost inevitable during the freezing of embryos. The present study examines the possibility of using high hydrostatic pressure to reduce substantially the freezing point of the embryo-holding solution, in order to preserve embryos at subzero temperatures, thus avoiding all the disadvantages of freezing. The pressure of 210 MPa lowers the phase transition temperature of water to -21°C. According to the results of this study, embryos can survive in high hydrostatic pressure environment at room temperature; the time embryos spend under pressure without significant loss in their survival could be lengthened by gradual decompression. Pressurisation at 0°C significantly reduced the survival capacity of the embryos; gradual decompression had no beneficial effect on survival at that stage. Based on the findings, the use of the phenomena is not applicable in this form, since pressure and low temperature together proved to be lethal to the embryos in these experiments. The application of hydrostatic pressure in embryo cryopreservation requires more detailed research, although the experience gained in this study can be applied usefully in different circumstances.

Photophysical properties of N719 and Z907 dyes, benchmark sensitizers for dye-sensitized solar cells, at room and low temperature

2021 ◽  
Vol 23 (10) ◽  
pp. 6182-6189
Author(s):  
Dariusz M. Niedzwiedzki
Keyword(s):  
Solar Cells ◽  
Low Temperature ◽  
Optical Spectroscopy ◽  
Room Temperature ◽  
Photophysical Properties ◽  
Dye Sensitized Solar Cells ◽  
Time Resolved ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

Photophysical properties of N719 and Z907, benchmark Ru-dyes used as sensitizers in dye-sensitized solar cells, were studied by static and time-resolved optical spectroscopy at room temperature and 160 K.

Transition Insulator-Metal and Antiferromagnetic-Paramagnetic Cu Doped in La0.47Ca0.53MnO3

2015 ◽  
Vol 1123 ◽  
pp. 73-77 ◽  
Author(s):  
Yohanes Edi Gunanto ◽  
K. Sinaga ◽  
B. Kurniawan ◽  
S. Poertadji ◽  
H. Tanaka ◽  
...  
Keyword(s):  
High Resolution ◽  
Low Temperature ◽  
Magnetic Structure ◽  
Room Temperature ◽  
Paramagnetic Phase ◽  
Perovskite Manganites ◽  
Antiferromagnetic Phase ◽  
Temperature Transition ◽  
Cu Doping ◽  
Metal State

The study of the perovskite manganites La0.47Ca0.53Mn1-xCuxO3 with x = 0, 0.06, 0.09, and 0.13 has been done. The magnetic structure was determined using high-resolution neutron scattering at room temperature and low temperature. All samples were paramagnetic at room temperature and antiferromagnetic at low temperature. Using the SQUID Quantum Design, the samples showed that the doping of the insulating antiferromagnetic phase La0.47Ca0.53MnO3 with Cu doping resulted in the temperature transition from an insulator to metal state, and an antiferromagnetic to paramagnetic phase. The temperature transition from an insulator to metal state ranged from 23 to 100 K and from 200 to 230 K for the transition from an antiferromagnetic to paramagnetic phase.

Electrical Characterization of Low Temperature GaAs Layers, and Observation of the Extremely Large Carrier Concentrations in Undoped Material

1991 ◽  
Vol 241 ◽  
Author(s):  
Bijan Tadayon ◽  
Mohammad Fatemi ◽  
Saied Tadayon ◽  
F. Moore ◽  
Harry Dietrich
Keyword(s):  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Substrate Temperature ◽  
Molecular Beam ◽  
Electrical Characterization ◽  
Physical Characteristics ◽  
Hall Measurements ◽  
Undoped Material ◽  
Low Temperature Gaas

ABSTRACTWe present here the results of a study on the effect of substrate temperature, Ts, on the electrical and physical characteristics of low temperature (LT) molecular beam epitaxy GaAs layers. Hall measurements have been performed on the asgrown samples and on samples annealed at 610 °C and 850 °C. Si implantation into these layers has also been investigated.

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