Characterization of Electrolytically Deposited CdSe on Ti Substrates

2010 ◽  
Vol 297-301 ◽  
pp. 912-917 ◽  
Author(s):  
T.G. Argyropoulos ◽  
Jelica Novakovic ◽  
M.D. Athanassopoulou ◽  
P. Vassiliou ◽  
J.A. Mergos ◽  
...  
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Surface Morphology ◽  
Bath Temperature ◽  
Vacuum Heat Treatment ◽  
Bath Solution ◽  
Zinc Blende ◽  
Zinc Blende Structure

Electrolytical deposition of CdSe on Ti substrates from CdSO4 - SeO2 solutions is investigated. The effect of the bath temperature was investigated and how it affects the CdSe deposits. According to the XRD spectra, the obtained CdSe films exhibit the cubic zinc-blende structure that remains unaffected by vacuum heat treatment (650°C). The surface morphology of the films differs significantly with bath solution temperatures. When Au contacts are used, the Ti/CdSe/Au structure may exhibit rectifying properties depending on the temperature during the electrodeposition. High temperature baths make the deposits to obtain ohmic properties.

Synthesis and Characterization of ZnS: Fe/ZnS Core-Shell Nanocrystals

2011 ◽  
Vol 148-149 ◽  
pp. 900-903
Author(s):  
Li Hua Li ◽  
Yong Jun Gu ◽  
Rui Shi Xie ◽  
Jian Guo Zhu
Keyword(s):  
Chemical Precipitation ◽  
Precipitation Method ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Pl Spectra ◽  
Zinc Blende ◽  
Diffraction Peaks ◽  
Zns Nanocrystals ◽  
Zinc Blende Structure

ZnS:Fe and ZnS:Fe/ZnS core-shell nanocrystals were synthesized by chemical precipitation method. It was found that the ZnS: Fe based nanocrystals possess zinc blende structure. Compared to ZnS: Fe nanocrystals, the intensity of the X-ray diffraction peaks of ZnS: Fe/ZnS nanocrystals reduced and these peaks moved to lower angles. TEM images show that ZnS: Fe based nanocrystals are spheroidal and the average particles size is about 3~4 nm. PL spectra of ZnS: Fe nanocrystals revealed several mission bands, ~406nm, ~444nm, ~416nm, However, PL spectra of ZnS: Fe/ZnS nanocrystals showed several mission bands, ~420nm, ~432nm, ~449nm.

Characterization of ZnSe Nanoparticles Prepared Using Ultrasonic Radiation Method

1998 ◽  
Vol 536 ◽  
Author(s):  
Jianfeng Xu ◽  
Wei Ji ◽  
Sing-Hai Tang ◽  
Wei Huang
Keyword(s):  
Xps Analysis ◽  
Phonon Modes ◽  
Znse Nanoparticles ◽  
Raman Scattering Spectroscopy ◽  
Ultrasonic Radiation ◽  
Radiation Method ◽  
Zinc Blende ◽  
Average Size ◽  
Zinc Blende Structure

AbstractZnSe nanoparticles with an average size of 15 nm were prepared using the ultrasonic radiation method. The characterization was carried out by means of XRD, TEM, XPS and Raman scattering spectroscopy. The experimental results indicate that the as-prepared powders are composed of ZnSe with zinc-blende structure. The high purity of ZnSe particles was confirmed by XPS analysis. In the Raman spectra, TO and LO phonon modes were observed at 205 and 257 cm−1 in the ZnSe nanoparticles.

Complex Characterization of a New Low Ni Maraging Steel with Enhance Service Stability

2012 ◽  
Vol 188 ◽  
pp. 346-351
Author(s):  
Mihai Branzei ◽  
Ion Nedelcu ◽  
Marian Miculescu
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Maraging Steel ◽  
Lath Martensite ◽  
Structure Stability ◽  
Treatment Technology ◽  
New Type ◽  
Optimum Heat ◽  
National Patent

A new low Ni maraging steel, based on 18Ni (300) type has been developed. The optimized chemical composition (complex alloyed with Al-Si-Ti or Si-Zr-Nb) in accordance with optimum heat treatment was found (solution: 970 °C/1h/air and ageing: 550 °C/3h/air), in order to obtain maximum service temperature of over 600 0C and ensured the good combination of strength and toughness properties. The precipitates, such as Ni3(Mo, Ti), were well controlled in lath martensite (Rm=2090N/mm2 and Rp0,2=1930N/mm2)and the presence of Si, Zr and Nb enhance structure stability at high temperature (for example the ultimate tensile strength at 5500C is about 1440N/mm2). Therefore, this new type of maraging steel was the subject of a national patent: “Maraging steel for high temperature service and heat treatment technology” – PATENT No.120356/30.08.2010.

Recent results of High Temperature Vacuum Heat Treatment program of SRF Resonators at IJCLab

2021 ◽  
pp. 1-1
Author(s):  
Mohammed Fouaidy ◽  
Frederic Chatelet ◽  
David Le Drean ◽  
David Longuevergne ◽  
Richard Martret ◽  
...  
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Treatment Program ◽  
Vacuum Heat Treatment

Characterization Of Flaws Produced By Mechanical Grinding Of Si3N4

1977 ◽  
Vol 35 ◽  
pp. 144-145
Author(s):  
Nancy J. Tighe
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Silicon Nitride ◽  
Mechanical Testing ◽  
Testing Temperature ◽  
Initial Population ◽  
Mechanical Grinding ◽  
Flexure Strength ◽  
Thin Foils

The flexure strength of silicon nitride is related to the size of flaws at or below the surface. These flaws typically are cracks which nucleate at ground surfaces or at internal inclusions. One crack from the population of flaws grows under the applied stress and causes failure. Recent mechanical testing experiments in this laboratory showed that high temperature (1200°C) exposure can either increase or decrease the strength of silicon nitride depending on the time of exposure and the testing temperature (1). Because this material oxidized readily at 1200°C, both oxidation and heat treatment changed the flaw population. The change in flaw population can be determined after nature of the initial population is established.The initial flaw population produced by grinding is being characterized by examining thin foils made from silicon nitride samples which had different surface treatments.

Synthesis and Characterization of Water-Soluble Cu2+-Doped ZnSe Quantum Dots

2009 ◽  
Vol 79-82 ◽  
pp. 2043-2046 ◽  
Author(s):  
Shan Shan Li ◽  
Fu Tian Liu ◽  
Qun Wang ◽  
Xiu Xiu Chen ◽  
Ping Yang
Keyword(s):  
Quantum Dots ◽  
Green Emission ◽  
Average Diameter ◽  
Water Soluble ◽  
X Ray ◽  
Zinc Blende ◽  
Transmission Electron ◽  
Uv Excitation ◽  
Zinc Blende Structure

Cu2+-doped ZnSe quantum dots (ZnSe:Cu) were prepared via a green and simple route, namely the chemical coprecipitation method. Under 365 nm UV excitation, green emission is observed. X-ray powder diffraction (XRD) shows that ZnSe:Cu nanoparticle is cubic zinc blende structure; the transmission electron microscopy (TEM) exhibits that the average diameter of ZnSe:Cu nanocrystals is less than 10 nm. UV-vis spectrophotometer and fluorescence spectrophotometer indicate that ZnSe:Cu nanocrystals have good fluorescence effects.

Study of Cuprous Oxide formed in Air at 0.5 mm of Hg between 200° C and 1030° C and its rectification

1957 ◽  
Vol 12 (2) ◽  
pp. 96-101 ◽  
Author(s):  
K. R. Dixit ◽  
V. V. Agashe
Keyword(s):  
Heat Treatment ◽  
Diamagnetic Susceptibility ◽  
Subsequent Heat Treatment ◽  
Appreciable Amount ◽  
Body Structure ◽  
X Ray ◽  
Zinc Blende ◽  
Plausible Mechanism ◽  
Composition Structure ◽  
Zinc Blende Structure

Oxides of copper formed at an air pressure 0.5 mm of Hg in the temperature range 200° C to 1030° C and for a time of formation of one hour have been studied. Their composition structure by the method of electron diffraction and X-ray reflection, rectification, and magnetic susceptibility — all these as a function of the subsequent heat treatment and the thickness of the film — have been investigated. The films formed at 500° C just begin to show rectification, it becomes appreciable at 800° C and then increases rapidly with the temperature of formation of the film. The rectifying films are all Cu2O films but with a peculiar structure. The appearance of an appreciable amount of rectification is accompanied by changes in the surface structure, body structure and the susceptibility of the films. For a rectifying film the surface layer consists of large Cu2O crystals showing 111 orientation. Below this small crystallites of Cu2O, including an excess of oxygen, and showing a zinc blende structure, are present. The effect of the subsequent heat treatment is to reduce the amount of oxygen and increase the diamagnetic susceptibility. A maximum rectification is obtained, when the Cu2O crystallites are fairly small and contain on an average an excess of one atom of oxygen per crystallite. A plausible mechanism for the changes is suggested.

scholarly journals Ageing of Zirconia Dedicated to Dental Prostheses for Bruxers Part 2: Influence of Heat Treatment for Surface Morphology, Phase Composition and Mechanical Properties

2019 ◽  
Vol 58 (1) ◽  
pp. 218-225
Author(s):  
Damian S. Nakonieczny ◽  
Agata Sambok ◽  
Magdalena Antonowicz ◽  
Marcin Basiaga ◽  
Zbigniew K. Paszenda ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Phase Composition ◽  
High Temperature ◽  
Surface Morphology ◽  
Aging Process ◽  
Negative Impact ◽  
Bending Test ◽  
High Temperature Heat Treatment ◽  
Dental Prostheses

Abstract Purpose: This part of the study focuses on the influence of zirconia heat treatment for surface morphology, phase composition and mechanical properties Methods: Zirconia samples was prepared with ISO 13356:2013 and ISO 14704:2008 recommendations. X-ray diffraction, observations (SEM) and (AFM), microhardness (Olivera & Phara method), and static bending test (4PBT) were taken. Results: characterization of YSZ and high temperature heat treatment has clearly shown that the aging process influences the change in phase composition of the material, significantly worsening the topography. In turn, re-treatment of the high temperature made after the artificial aging process results in reverse transformation of the desired tetragonal phase, but does not affect the improvement of surface morphology. Conclusions: The research made it possible to assess the negative impact of the zirconium oxide aging simulation process. Because of the failure to achieve the intended results, it was also proved that the high-temperature re-processing was not appropriate.

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