Controllable phase transformation and improved thermal stability of nickel on tungsten substrate by electrodeposition

2019 ◽  
Vol 35 (5) ◽  
pp. 727-732
Author(s):  
Minjie Xu ◽  
Chao Hu ◽  
Haiyan Xiang ◽  
Haozi Lu ◽  
Travis Shihao Hu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Phase Transformation ◽  
Thermal Stability Of ◽  
Tungsten Substrate

scholarly journals ALUMINA PHASE TRANSFORMATION FROM THERMAL DECOMPOSITION OF AMMONIUM ALUM SYNTHESIZED FROM KANKARA KAOLIN

2017 ◽  
Vol 36 (3) ◽  
pp. 822-828
Author(s):  
SG Bawa ◽  
AS Ahmed ◽  
PC Okonkwo
Keyword(s):  
Thermal Stability ◽  
Phase Transformation ◽  
Calcination Temperature ◽  
Starting Material ◽  
Gamma Alumina ◽  
X Ray ◽  
Alumina Phase ◽  
Ammonium Alum ◽  
Alpha Alumina ◽  
Thermal Stability Of

Thermal stability of transitional alumina phases produced from ammonium alum using Kankara kaolin as starting material was studied. Wet beneficiation method was employed to purify the starting material, after which it was calcined and dealuminated with sulphuric acid. The elemental composition, mineralogical, and physiological analyses were carried out using X-ray fluorescence (XRF), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) techniques respectively. The ammonium alum was thermally treated by varying the calcination temperature from 700 to 1200°C and varying the time of calcination from 1 to 4 h. The formation of gamma alumina began at calcination temperature of 825°C for calcination time of 3 h, which was found to be lower than reported works of 900°C. It was found to be stable at higher temperature of 1125°C, above which phase transformation to alpha alumina was observed. The observed wide range of thermal stability of the gamma alumina phase gives it good advantage to be used for high temperature applications, such as support for catalyst promoters. Alpha alumina phase formation began at 1150°C and was fully formed at 1200°C. BET specific surface area of 166 m2/g was obtained for the gamma alumina phase which was high enough for it application as support for catalyst, catalyst and adsorbent. http://dx.doi.org/10.4314/njt.v36i3.23

scholarly journals Pulsed direct current field-induced thermal stability and phase transformation of nanodiamonds to carbon onions

RSC Advances ◽  
2019 ◽  
Vol 9 (25) ◽  
pp. 14360-14371 ◽  
Author(s):  
Faming Zhang ◽  
Kuowei Fan ◽  
Jin Yu ◽  
Farhad Saba ◽  
Jing Sun
Keyword(s):  
Thermal Stability ◽  
Phase Transformation ◽  
Direct Current ◽  
Current Field ◽  
Detailed Understanding ◽  
Pulsed Dc ◽  
Carbon Onions ◽  
Pulsed Direct Current ◽  
Thermal Stability Of

The pulsed DC field-induced thermal stability of nanodiamonds (NDs) and their transformation to carbon onions lack detailed understanding.

Study on Modification of Hitec Molten Salt and its Properties Tests

2014 ◽  
Vol 1073-1076 ◽  
pp. 66-72
Author(s):  
Wei Zhai ◽  
Guang Ming Liu ◽  
Fei Yu ◽  
Yuan Kui Wang
Keyword(s):  
Thermal Stability ◽  
Phase Transformation ◽  
Melting Point ◽  
Molten Salt ◽  
Latent Heat ◽  
Molten Salts ◽  
Heat Storage ◽  
Heat Of Fusion ◽  
Temperature Heat ◽  
Thermal Stability Of

In this paper, additive A and additive B were added into Hitec molten salts in order to optimize the properties of the molten salt. The melting point, latent heat of phase transformation, specific heat capacity, thermal gravity, and thermal stability of the modified Hitec molten salt was characterized. The results showed that compare to Hitec molten salt the modified Hitec molten salt showed low melting point, proper latent heat of phase transformation, greater heat of fusion, wide using temperature range and other advantages. The modified molten salt had good thermal properties and thermal stability. This modified Hitec molten salt has good application prospect in the aspect of high temperature heat storage/transfer.

AEM Study on the Phase Transformation of Nickel Silicides in the Ni1-xTax/Si System

2007 ◽  
Vol 124-126 ◽  
pp. 45-48
Author(s):  
J.W. Lee ◽  
Cheol Woong Yang
Keyword(s):  
Thermal Stability ◽  
Phase Transformation ◽  
Analytical Electron Microscopy ◽  
Convergent Beam Electron Diffraction ◽  
Phase Identification ◽  
Post Heat Treatment ◽  
Silicide Layer ◽  
Analytical Electron ◽  
Convergent Beam ◽  
Thermal Stability Of

We investigated the phase transformation and thermal stability of Ni silicides formed in Ni/Si and Ni0.95Ta0.05/Si systems. The sheet resistance values of the silicide in the Ni0.95Ta0.05/Si system were lower than those in Ni/Si system at any temperature. The enhancement of thermal stability is closely related to the phase transformation occurred during post heat-treatment. Microstructure of the phases formed by reaction was investigated by analytical electron microscopy (AEM) and the phase identification of Ni silicide was carried out using convergent beam electron diffraction (CBED) technique. It was found that a Ta rich layer formed on the top of the Ni silicide layer and small amount of Ta dissolved into the silicide layer. By addition of Ta atoms, phase transformation from NiSi to NiSi2 is retarded and thermal stability of Ni silicide is improved.

Influence of Al addition on phase transformation and thermal stability of nickel silicides on Si(001)

2014 ◽  
Vol 586 ◽  
pp. S362-S367 ◽  
Author(s):  
Shih-Hsien Huang ◽  
Sheng-Chen Twan ◽  
Shao-Liang Cheng ◽  
Tu Lee ◽  
Jung-Chih Hu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Phase Transformation ◽  
Nickel Silicides ◽  
Al Addition ◽  
Thermal Stability Of

Phase transformation and thermal stability of ZnSe QDs due to annealing: emergence of ZnO

2016 ◽  
Vol 27 (9) ◽  
pp. 8871-8878 ◽  
Author(s):  
M. Verma ◽  
A. Kaswan ◽  
D. Patidar ◽  
K. B. Sharma ◽  
N. S. Saxena
Keyword(s):  
Thermal Stability ◽  
Phase Transformation ◽  
Thermal Stability Of

Phase transformation and thermal stability of mechanically alloyed W–Ni–Fe composite materials

2004 ◽  
Vol 379 (1-2) ◽  
pp. 148-153 ◽  
Author(s):  
Zhong-Wu Zhang ◽  
Jing-En Zhou ◽  
Sheng-Qi Xi ◽  
Guang Ran ◽  
Peng-Liang Li
Keyword(s):  
Thermal Stability ◽  
Phase Transformation ◽  
Composite Materials ◽  
Mechanically Alloyed ◽  
Thermal Stability Of

Thermal Stability of High k Layers

2002 ◽  
Vol 745 ◽  
Author(s):  
C. Zhao ◽  
V. Cosnier ◽  
P. J. Chen ◽  
O. Richard ◽  
G. Roebben ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Phase Transformation ◽  
Surface Preparation ◽  
Thermal Exposure ◽  
Amorphous Phases ◽  
High K ◽  
M Phase ◽  
Crystallization Onset Temperatures ◽  
Spike Annealing ◽  
Thermal Stability Of

ABSTRACTThermal stability of amorphous phases in various high-k layers (Al2O3, ZrO2, HfO2, ZrAlOx, HfAlOx and HfSiOx) and the phase transformation of crystalline ZrO2 and HfO2 were studied experimentally, as functions of surface preparation, deposition conditions, material composition and post deposition thermal treatment. It is found that pure ZrO2 and HfO2 show relatively low crystallization onset temperatures. The crystalline ZrO2 or HfO2 phases are tetragonal or monoclinic, depending on the layer thickness. The phase transformation of metastable t-phase into stable m-phase has been observed in ZrO2 and HfO2. Crystallization behavior of Al2O3 depends on the surface preparation of the substrate. ALCVD grown Al2O3 layers on an oxide-based surface remain amorphous after 1100°C spike annealing, while those on HF-last surface crystallize at temperatures around 800°C. Alloying Al2O3 into ZrO2 and HfO2 can improve their resistance to crystallization under thermal exposure. The kinetics of the crystallization in the alloys can be described by linear TTT curves. Hf-aluminates show better thermal stability than Zr-aluminates. A defect model relative to the phase transformation is discussed, based on the above observations.

Thermal Stability of Supported Titania Membranes

1992 ◽  
Vol 271 ◽  
Author(s):  
Krishnankutty-Nair P. Kumar ◽  
V. T. Zaspalis ◽  
F. F. M. De Mul ◽  
Klaas Keizer ◽  
Anthonie J. Burggraaf
Keyword(s):  
Thermal Stability ◽  
Raman Spectroscopy ◽  
Phase Transformation ◽  
Transformation Temperature ◽  
Rutile Phase ◽  
Phase Transformation Temperature ◽  
Supported Membranes ◽  
Beneficial Effects ◽  
The Difference ◽  
Thermal Stability Of

ABSTRACTThe beneficial effects of the support constraint on the improved thermal stability of supported titania membranes were studied by following the anatase to rutile phase transformation in supported and unsupported titania membranes. This was studied using Raman spectroscopy and XRD. Supported membranes showed a higher transformation temperature, about 150°C higher, (slower rate of transformation) compared to the unsupported ones. Unsupported membranes showed a slight thickness dependence on the phase transformation temperature, but less significant compared to the difference in phase transformation behaviour between supported and unsupported membranes of similar thicknesses.

Sign in / Sign up

Export Citation Format

Share Document