scholarly journals Correlation between thermal annealing temperature and Joule-heating based insulator-metal transition in VO2 nanobeams

2013 ◽  
Vol 103 (20) ◽  
pp. 203114 ◽  
Author(s):  
Servin Rathi ◽  
Jin-Hyung Park ◽  
In-yeal Lee ◽  
Min Jin Kim ◽  
Jeong Min Baik ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Joule Heating ◽  
Annealing Temperature ◽  
Insulator Metal Transition

Correlation between crystallinity and mid-infrared optical absorption spectra of silicon supersaturated with sulfur

2015 ◽  
Vol 1738 ◽  
Author(s):  
Ikurou Umezu ◽  
Katsuki Nagao ◽  
Tatsuya Nakai ◽  
Muneyuki Naito ◽  
Mitsuru Inada ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Single Crystal ◽  
Thermal Annealing ◽  
Laser Fluence ◽  
Annealing Temperature ◽  
Pulsed Laser ◽  
Single Crystal Substrate ◽  
Laser Melting ◽  
Mid Infrared ◽  
Insulator Metal Transition

ABSTRACTWe prepared silicon hyperdoped with sulfur by ion-implantation followed by pulsed laser melting. Effects of laser fluence during pulsed laser melting and of post-annealing on the silicon hyperdoped with sulfur are investigated. The structure of hyperdoped layer changes from poly-to mono-crystal with increasing laser fluence. Interface between sulfur-implanted-layer and single-crystal substrate disappear above 1.1 J/cm2. The spectral intensity of mid-infrared (MIR) optical absorption increases with crystallinity and spectral shape depends on whether the melt depth during pulsed laser melting reaches interface between implanted layer and single-crystal silicon substrate or not. The MIR absorption intensity rapidly decreases with thermal annealing temperature and almost disappears at 750 °C. The activation energy of conductivity decreases with increasing laser fluence and further decreases with increasing post thermal-annealing temperature. The insulator-metal transition is observed for the sample annealed at 750 °C. These results indicate that there is no direct correlation between MIR optical absorption band and insulator-metal transition.

Nickel Oxide Coated on Pretreated MWCNTs as an Electrode for Supercapacitor

2013 ◽  
Vol 829 ◽  
pp. 654-658
Author(s):  
Lida Mahmoudi ◽  
Farzad Mahboubi ◽  
Moreteza Saghafi Yazdi
Keyword(s):  
Nickel Oxide ◽  
Thermal Annealing ◽  
Nickel Hydroxide ◽  
Annealing Temperature ◽  
Electrochemical Characteristics ◽  
Sem Images ◽  
Electroactive Materials ◽  
Nanotubular Structure ◽  
Individual Cnts ◽  
The Individual

Nickel oxide/carbon nanotubes (NiO/CNTs) composite materials for supercapacitor are prepared by chemically depositing of nickel hydroxide onto CNTs pretreated by ultrasonication and followed by thermal annealing at 200-300°C. A series of NiO/CNTs composites with different weight ratios of CNTs and different annealing temperature are synthesized via the same route. The scanning electron microscope (SEM) images show that the nucleation of the nickel hydroxide formed on the outer walls of CNTs due to ultrasonic cavitations, and then nickel oxide coated uniformly on the outer surface of the individual CNTs after thermal annealing. The NiO/CNTs electrode presents a maximum specific capacitance of 254 F/g as well as a good cycle life in 2 M KOH electrolyte. The good electrochemical characteristics of NiO/CNTs composite can be attributed to the three-dimensionally interconnected nanotubular structure with a thin film of electroactive materials.

Investigation of the influence of the mode of heat treatment of the initial powder on the efficiency of sintering zirconium ceramics by dilatometry

2021 ◽  
Vol 103 (3) ◽  
pp. 17-24
Author(s):  
S. Shevelev ◽  
◽  
E. Sheveleva ◽  
O. Stary ◽  
Keyword(s):  
Thermal Annealing ◽  
Zirconium Dioxide ◽  
Annealing Temperature ◽  
Average Particle Size ◽  
Average Particle ◽  
Sintered Ceramic ◽  
Tetragonal Modification ◽  
Thermal Sintering ◽  
Powder Compacts ◽  
High Degree

Using methods of synchronous thermal and X-ray structural analyzes applied to zirconium dioxide powders partially stabilized with yttrium obtained by chemical coprecipitation the processes of dehydration of these powders during annealing in air have been investigated. Using the dilatometry method, the regularities of compaction of powder compacts have been investigated with thermal sintering. It was found that the resulting powders mainly consist of the tetragonal modification zirconium dioxide and are nano-sized. The average particle size was 25 nm. The resulting powders are characterized by a high degree of agglomeration. It is shown that an increase in the thermal annealing temperature from 500 to 700ºС leads to partial baking of individual particles inside the agglomerate, and causes the formation of hard agglomerates, the presence of which complicates the processes of compaction and subsequent sintering. The presence of such agglomerates prevents the production of ceramics with high mechanical characteristics: density and porosity. Thermal annealing temperature increase leads to a decrease in the density of the sintered ceramic and a decrease in its hardness.

scholarly journals Synthesis of Ge1−xSnx Alloy Thin Films by Rapid Thermal Annealing of Sputtered Ge/Sn/Ge Layers on Si Substrates

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2248 ◽  
Author(s):  
Hadi Mahmodi ◽  
Md Hashim ◽  
Tetsuo Soga ◽  
Salman Alrokayan ◽  
Haseeb Khan ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Near Infrared ◽  
Annealing Temperature ◽  
Solid Phase ◽  
Infrared Region ◽  
Alloy Formation ◽  
Phase Mixing ◽  
Si Substrates ◽  
Msm Photodetector

In this work, nanocrystalline Ge1−xSnx alloy formation from a rapid thermal annealed Ge/Sn/Ge multilayer has been presented. The multilayer was magnetron sputtered onto the Silicon substrate. This was followed by annealing the layers by rapid thermal annealing, at temperatures of 300 °C, 350 °C, 400 °C, and 450 °C, for 10 s. Then, the effect of thermal annealing on the morphological, structural, and optical characteristics of the synthesized Ge1−xSnx alloys were investigated. The nanocrystalline Ge1−xSnx formation was revealed by high-resolution X-ray diffraction (HR-XRD) measurements, which showed the orientation of (111). Raman results showed that phonon intensities of the Ge-Ge vibrations were improved with an increase in the annealing temperature. The results evidently showed that raising the annealing temperature led to improvements in the crystalline quality of the layers. It was demonstrated that Ge-Sn solid-phase mixing had occurred at a low temperature of 400 °C, which led to the creation of a Ge1−xSnx alloy. In addition, spectral photo-responsivity of a fabricated Ge1−xSnx metal-semiconductor-metal (MSM) photodetector exhibited its extending wavelength into the near-infrared region (820 nm).

Effects of thermal annealing temperature and duration on hydrothermally grown ZnO nanorod arrays

2009 ◽  
Vol 255 (11) ◽  
pp. 5861-5865 ◽  
Author(s):  
X.Q. Zhao ◽  
C.R. Kim ◽  
J.Y. Lee ◽  
C.M. Shin ◽  
J.H. Heo ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Annealing Temperature ◽  
Zno Nanorod ◽  
Nanorod Arrays ◽  
Zno Nanorod Arrays

Ajustement par recuits rapides RTA (rapid thermal annealing) des contraintes dans des couches minces de tungstène utilisées comme absorbant pour des masques à rayons X

1991 ◽  
Vol 69 (3-4) ◽  
pp. 451-455 ◽  
Author(s):  
H. Lafontaine ◽  
J. F. Currie ◽  
S. Boily ◽  
M. Chaker ◽  
H. Pépin
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Annealing Temperature ◽  
Rf Power ◽  
X Ray ◽  
Stress Changes ◽  
Different Temperatures ◽  
Absorbing Layer ◽  
Good Agreement ◽  
Sputtering System

Tungsten thin films are deposited with a triode sputtering system in order to obtain an absorbing layer for X-ray masks. The mechanical stress is studied as a function of different pressure and RF power conditions during deposition. Rapid thermal annealing at different temperatures and durations is performed in order to produce films under low compressive stress. We observe that the stress changes occur over the time scale of seconds at the annealing temperature and that the corresponding activation energies are low (60 meV). Grain growth in a preferred orientation explains the observed changes in stress. The magnitude in the change of stress is in good agreement with a model proposed by Hoffman et al. relating the stress to grain size and grain boundary dimensions. [Journal translation]

scholarly journals Effect of rapid thermal annealing on structural and optical properties of ZnS thin films fabricated by RF magnetron sputtering technique

2019 ◽  
Vol 14 (1) ◽  
pp. 53-63 ◽  
Author(s):  
M. S. Bashar ◽  
Rummana Matin ◽  
Munira Sultana ◽  
Ayesha Siddika ◽  
M. Rahaman ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Carrier Concentration ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Annealing Temperature ◽  
Annealing Treatment ◽  
Localized States ◽  
Stoichiometric Ratio ◽  
Deposited Films

AbstractThe ZnS thin films have been deposited by radio frequency magnetron sputtering at room temperature. Post-deposition rapid thermal annealing treatment was done for the films deposited at different powers ranging from 70 to 100 W. One peak is observed for as-deposited and annealed thin films at around 28.48° corresponding to the (111) reflection plane indicating a zincblende structure. The overall intensity of the peaks and the FWHM values of as-deposited films increased after annealing corresponding to the increase in crystallinity. The optical energy bandgap is found in the range of 3.24–3.32 eV. With increasing annealing temperature, the decrease in the Urbach energy values indicating a decrease in localized states which is in good agreement with the XRD results where the crystallinity increased. The surface morphology of the films seems to be composed of Nano-granules with a compact arrangement. Apparently, the grain size increases in the deposited films as annealing temperature increases. The compositional ratio attained close to the stoichiometric ratio of 1:1 after annealing. From the Hall effect measurement, the carrier concentration and mobility are found to increase after annealing. The high carrier concentration and mobility also comply with structural and optical analysis. Best results are found for the film annealed at 400 °C deposited at 90 W.

Evolution of Photoluminescence Mechanisms of Si+-Implanted SiO2 Films with Thermal Annealing

2008 ◽  
Vol 8 (7) ◽  
pp. 3555-3560 ◽  
Author(s):  
L. Ding ◽  
T. P. Chen ◽  
Y. Liu ◽  
C. Y. Ng ◽  
M. Yang ◽  
...  
Keyword(s):  
Band Structure ◽  
Thermal Annealing ◽  
Annealing Temperature ◽  
Energy Gap ◽  
The Other ◽  
Extended Defects ◽  
Band Transition ◽  
Luminescent Centers ◽  
Subsequent Thermal Annealing ◽  
Si Ion Implantation

The information of band structure of silicon nanocrystal (nc-Si) embedded in SiO2 thin films synthesized by Si ion implantation and subsequent thermal annealing at various temperatures has been obtained from spectroscopy ellipsometric (SE) analysis. The indirect band structure and the energy gap of the nc-Si are not affected by the annealing. In contrast, the photoluminescence (PL) spectra show a continuous evolution with the annealing. Six PL bands located at 415, 460, 520, 630, 760, and 845 nm, respectively, have been observed depending on the annealing temperature. The annealing at 1100 °C yields the strongest PL band at 760 nm (∼1.63 eV) with the intensity much higher than that of all the other PL bands. Based on the knowledge of the band structure, the 760 nm-PL band could be attributed to the indirect band-to-band transition of the nc-Si assisted by the Si—O vibration of the nc-Si/SiO2 interface with the stretching frequency of ∼1083 cm−1 (&sim0.13 eV). On the other hand, the first four PL bands mentioned above could originate from different extended defects in the oxide matrix, while the 845-nm PL band could be related to the interface luminescent centers.

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