scholarly journals Effect of oxygen gas pressure on the kinetics of alumina film growth during the oxidation of Al(111) at room temperature

2011 ◽  
Vol 84 (12) ◽  
Author(s):  
Na Cai ◽  
Guangwen Zhou ◽  
Kathrin Müller ◽  
David E. Starr
Keyword(s):  
Room Temperature ◽  
Film Growth ◽  
Gas Pressure ◽  
Alumina Film ◽  
Oxygen Gas ◽  
Effect Of Oxygen ◽  
Kinetics Of

Effect of oxygen gas pressure on orientations of Cu2O nuclei during the initial oxidation of Cu(100), (110) and (111)

2012 ◽  
Vol 606 (23-24) ◽  
pp. 1790-1797 ◽  
Author(s):  
Langli Luo ◽  
Yihong Kang ◽  
Judith C. Yang ◽  
Guangwen Zhou
Keyword(s):  
Gas Pressure ◽  
Initial Oxidation ◽  
Oxygen Gas ◽  
Effect Of Oxygen

Growth of (Ba, Sr)TiO3 thin films by the hydrothermal-electrochemical method and effect of oxygen evolution on their microstructure

1996 ◽  
Vol 11 (1) ◽  
pp. 169-183 ◽  
Author(s):  
Koji Kajiyoshi ◽  
Masahiro Yoshimura ◽  
Yukio Hamaji ◽  
Kunisaburo Tomono ◽  
Toru Kasanami
Keyword(s):  
Thin Films ◽  
Solid Solution ◽  
Aqueous Solutions ◽  
Oxygen Evolution ◽  
Electrochemical Method ◽  
Gas Pressure ◽  
Oxygen Gas ◽  
Hydrothermal Electrochemical Method ◽  
Effect Of Oxygen ◽  
Crater Shape

Thin films in the system BaTiO3–SrTiO3 have been grown on Ti electrodes with control of the Ba/Sr composition in aqueous solutions of (Ba, Sr) (OH)2 by the hydrothermal-electrochemical method. Barium contents of the solid-solution films were always lower than those of the synthesis solutions used. The BaTiO3 and the (Ba, Sr)TiO3 solid-solution films included “crater-shape” defects that resulted from the breakaway of the growing film, whereas no such defects were observed in the SrTiO3 film. This dependence of the defect generation on the film composition was interpreted to be caused by differences of anodically evolved oxygen gas pressure in “short-circuiting paths” that exists characteristically in the films grown by this method.

Room-Temperature Kinetics of Short-Chain Alkanethiol Film Growth on Ag(111) from the Vapor Phase

2006 ◽  
Vol 110 (14) ◽  
pp. 7095-7097 ◽  
Author(s):  
Luis M. Rodríguez ◽  
J. Esteban Gayone ◽  
Esteban A. Sánchez ◽  
Oscar Grizzi ◽  
Bárbara Blum ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Room Temperature ◽  
Film Growth ◽  
Short Chain ◽  
Kinetics Of

Effect of Oxygen on Diamond Deposition in CH4/O2/H2 Gas Mixtures

1993 ◽  
Vol 334 ◽  
Author(s):  
H. Matsuyama ◽  
N. Sato ◽  
H. Kawakami
Keyword(s):  
Film Growth ◽  
Microwave Plasma ◽  
Gas Mixtures ◽  
Carbon Films ◽  
Diamond Growth ◽  
Growth Region ◽  
Gas Concentration ◽  
Oxygen Gas ◽  
Effect Of Oxygen ◽  
Plasma Emission Spectroscopy

AbstractDiamond growth experiments were carried out by a microwave plasma assisted CVD technique in various gas mixtures of CH4(0–100%)/02/H2. The phase diagram obtained by this study shows that a diamond growth region exists. With addition of more than 5% O2 in reactant gases, diamond particles could be included in amorphous or graphitic carbon films even using CH4/O2 gas mixtures. Faceted diamond films were obtained if the oxygen gas concentration [O2] was approximately more than half the methane gas concentration [CH4] ([O2]>[CH4]/2). However, no films were grown when [O2] exceeded half of [CH4] plus 7% ([O2]>[CH4]/2+7%). These results corresponded to the observations by plasma emission spectroscopy. Though oxygen etches carbon films and decomposes methane by forming carbon monoxide, oxygen rarely reacts with hydrogen in a film growth region.

Investigation of irradiation-induced nucleation processes in silicon and germanium

1995 ◽  
Vol 53 ◽  
pp. 224-225
Author(s):  
Harry A. Atwater ◽  
C.M. Yang ◽  
K.V. Shcheglov
Keyword(s):  
Room Temperature ◽  
Crystal Size ◽  
Initial Distribution ◽  
Engineering Control ◽  
Size Evolution ◽  
Silicon And Germanium ◽  
Ge Quantum Dot ◽  
And Control ◽  
Germanium Quantum Dots ◽  
Kinetics Of

Studies of the initial stages of nucleation of silicon and germanium have yielded insights that point the way to achievement of engineering control over crystal size evolution at the nanometer scale. In addition to their importance in understanding fundamental issues in nucleation, these studies are relevant to efforts to (i) control the size distributions of silicon and germanium “quantum dots𠇍, which will in turn enable control of the optical properties of these materials, (ii) and control the kinetics of crystallization of amorphous silicon and germanium films on amorphous insulating substrates so as to, e.g., produce crystalline grains of essentially arbitrary size.Ge quantum dot nanocrystals with average sizes between 2 nm and 9 nm were formed by room temperature ion implantation into SiO2, followed by precipitation during thermal anneals at temperatures between 30°C and 1200°C[1]. Surprisingly, it was found that Ge nanocrystal nucleation occurs at room temperature as shown in Fig. 1, and that subsequent microstructural evolution occurred via coarsening of the initial distribution.

Comparative Labelling and Biokinetic Studies of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn)

1977 ◽  
Vol 16 (01) ◽  
pp. 30-35 ◽  
Author(s):  
N. Agha ◽  
R. B. R. Persson
Keyword(s):  
Complex Formation ◽  
Significant Influence ◽  
Room Temperature ◽  
Ph Value ◽  
Maximum Activity ◽  
Reduction Step ◽  
Labelling Yield ◽  
Different Temperatures ◽  
Kinetics Of

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

Kinetics of the Thermal Disappearance of Radicals Formed During the Radiolysis of Aspartic Acid

2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Mihai Contineanu ◽  
iulia Contineanu ◽  
Ana Neacsu ◽  
Stefan Perisanu
Keyword(s):  
Thermal Resistance ◽  
Aspartic Acid ◽  
Room Temperature ◽  
Esr Spectra ◽  
Complex Mechanism ◽  
Radical Species ◽  
Mechanisms Of Formation ◽  
Kinetics Of

The radiolysis of the isomers L-, D- and DL- of the aspartic acid, in solid polycrystalline state, was investigated at room temperature. The analysis of their ESR spectra indicated the formation of at least two radicalic entities. The radical, identified as R3, resulting from the deamination of the acid, exhibits the highest concentration and thermal resistance. Possible mechanisms of formation of three radical species are suggested, based also on literature data. The kinetics of the disappearance of radical R3 indicated a complex mechanism. Three possible variants were suggested for this mechanism.

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