THE PHOTOLYSIS OF AZOISOPROPANE

1953 ◽  
Vol 31 (4) ◽  
pp. 377-384 ◽  
Author(s):  
R. W. Durham ◽  
E. W. R. Steacie
Keyword(s):  
Activation Energy ◽  
Room Temperature ◽  
Excited Molecule ◽  
Energy Difference ◽  
Effect Of Pressure ◽  
Temperature Range ◽  
Excited Molecules

Azoisopropane has been photolyzed by 3600 Å radiation over the temperature range 30–120 °C. The effect of pressure indicates an excited molecule mechanism. Excited molecules which decompose give nitrogen and isopropyl radicals; the latter either combine, disproportionate, or react with azoisopropane. The activation energy difference between the two reactions[Formula: see text]has been found to be 6.5 ± 0.5 kcal. per mole.The difference in activation energy between the disproportionation and combination reactions is rendered ambiguous by the possibility of C3H7.N:N existing at the lower temperatures; but this is certainly small. The ratio of the rates of the two reactions is 0.5 at room temperature.

About the Electrical Activation of 1×1020 cm-3 Ion Implanted Al in 4H-SiC at Annealing Temperatures in the Range 1500 - 1950°C

2018 ◽  
Vol 924 ◽  
pp. 333-338 ◽  
Author(s):  
Roberta Nipoti ◽  
Alberto Carnera ◽  
Giovanni Alfieri ◽  
Lukas Kranz
Keyword(s):  
Activation Energy ◽  
Sheet Resistance ◽  
Annealing Time ◽  
Thermal Activation ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Thermal Activation Energy ◽  
Electrical Activation ◽  
Temperature Range ◽  
Annealing Temperatures

The electrical activation of 1×1020cm-3implanted Al in 4H-SiC has been studied in the temperature range 1500 - 1950 °C by the analysis of the sheet resistance of the Al implanted layers, as measured at room temperature. The minimum annealing time for reaching stationary electrical at fixed annealing temperature has been found. The samples with stationary electrical activation have been used to estimate the thermal activation energy for the electrical activation of the implanted Al.

THE MERCURY PHOTOSENSITIZED HYDROGENATION OF PROPYLENE AND THE ACTIVATION ENERGY OF THE REACTION C3H7+H2 = C3H8+H

1955 ◽  
Vol 33 (4) ◽  
pp. 580-588 ◽  
Author(s):  
G. R. Hoey ◽  
D. J. Le Roy
Keyword(s):  
Activation Energy ◽  
Hydrogen Pressure ◽  
Room Temperature ◽  
Linear Functions ◽  
Analogous Reaction ◽  
Temperature Range ◽  
Pressure Decrease

The reactions initiated in hydrogen–propylene mixtures by Hg(3P1) atoms were studied over the temperature range from room temperature to 320 °C. At 260° and above, the rate of formation of propane and the rate of pressure decrease are linear functions of the hydrogen pressure. This effect is attributed to the reaction C3H7+H2 = C3H8+H and its activation energy is estimated to be equal to or slightly greater than 12.5 kcal. per mole. This is 1.2 kcal. per mole greater than the corrected value for the activation energy of the analogous reaction C2H5+H2 = C2H6+H. The ratio kcombination/kdispropotionation is estimated to be approximately 2.0 at room temperature in the case of isopropyl radicals.

REACTIONS OF ALKOXY RADICALS: V. PHOTOLYSIS OF DI-t-BUTYL PEROXIDE

1958 ◽  
Vol 36 (9) ◽  
pp. 1227-1232 ◽  
Author(s):  
Garnett McMillan ◽  
M. H. J. Wijnen
Keyword(s):  
Activation Energy ◽  
Carbon Monoxide ◽  
Energy Difference ◽  
Butyl Alcohol ◽  
Reaction Products ◽  
Butyl Ether ◽  
Alkoxy Radicals ◽  
Temperature Range ◽  
Butyl Peroxide ◽  
Butoxy Radical

The photolysis of di-t-butyl peroxide has been investigated over the temperature range 25 ° to 79 °C. As reaction products were observed: acetone, t-butyl alcohol, methyl t-butyl ether, i-butylene oxide, ethane, methane, and carbon monoxide. The following reactions, involving the t-butoxy radical, have been studied:[Formula: see text]An activation energy difference of E2 − E6 = 3 kcal has been obtained.

THE EFFECT OF PRESSURE ON THE ELECTRICAL RESISTANCE OF RUBIDIUM

1957 ◽  
Vol 35 (6) ◽  
pp. 720-729 ◽  
Author(s):  
J. S. Dugdale ◽  
J. A. Hulbert
Keyword(s):  
Low Temperature ◽  
Electrical Resistance ◽  
Room Temperature ◽  
Residual Resistivity ◽  
Effect Of Pressure ◽  
Temperature Range ◽  
Fluid State

By using helium in both the solid and the fluid state as a pressure-transmitting medium, it has been possible to measure the resistance of rubidium over the temperature range from 2° K. to room temperature at pressures up to 2500 atmospheres. In particular the effect of pressure on the transition at ~200° K., on the low temperature ideal resistivity, and on the residual resistivity was examined.

Kinetics of Cu Segregation in Al-Cu(1at% Cu) Interconnects Studied by Resistance Measurements

1997 ◽  
Vol 473 ◽  
Author(s):  
A. J. Kalkman ◽  
A. H. Verbruggen ◽  
G. C. A. M. Janssen ◽  
S. Radelaar
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Grain Boundary ◽  
Room Temperature ◽  
Boundary Diffusion ◽  
Measurement Temperature ◽  
Temperature Range ◽  
Different Temperatures ◽  
Resistance Decrease ◽  
Kinetics Of

ABSTRACTThe time-dependence of the growth of Al2Cu precipitates in Al-Cu(lat% Cu) thin films is studied by means of resistance measurements at different temperatures. The samples are annealed at 400°C for 1 hour, and then quickly cooled down to room temperature. Afterwards, the samples are heated within one minute to a measurement temperature between 140 °C and 240 °C. Growth of precipitates causes a well defined decrease in resistance. The observed resistance decrease does not follow an exponential decay. In the investigated temperature range the resistance decrease can be accurately modelled by (R(t)-R∞) = (Ro-R∞)exp(-(t /τ)n), with the time constant τ= τ0 exp(Ea / kT). Excellent fits were obtained resulting in n = 0.66±0.05, independent of temperature, and Ea= 0.81±0.03 eV. This value for the activation energy agrees very well with the activation energy that has been reported in literature for both electromigration failure in Al-Cu and grain-boundary diffusion of Cu in Al. The value we found for n is intriguingly close to 2/3 and deviates strongly from the values of n reported for bulk Al-Cu (n = 1.5–1.8) in the same temperature range.

Luminescence Properties of Eu ion-implanted GaN

2003 ◽  
Vol 798 ◽  
Author(s):  
Shin-ichiro Uekusa ◽  
Isao Tanaka
Keyword(s):  
Activation Energy ◽  
Electron Emission ◽  
Radiative Recombination ◽  
Room Temperature ◽  
Thermal Quenching ◽  
Temperature Dependent ◽  
Room Temperature Photoluminescence ◽  
Temperature Range ◽  
Quenching Process ◽  
The Eu

ABSTRACTThe Eu ion was implanted at an energy of 300keV with a dose of 1×1015cm-2 at room temperature. Photoluminescence (PL) and PL lifetime were characterized and studied on thermal quenching process. We calculated the activation energy (E1) of temperature dependent PL and the value of E1 was 5.68meV. E1 was affected the luminescence intensity in the temperature range from 15K to 70K. The activation energy (Ea) of PL lifetime was calculated and the value of Ea was 8.5meV. The non-radiative recombination in the transition from the 5D0 to 7F2 of Eu was dominated in the temperature range from 15K to 100K. We found that the thermal quenching occurred in both the electron emission from RE-trap and the non-radiative recombination in the transition on Eu in the temperature range from 15K to 70K.

THE PYROLYSIS OF DIALLYL (1,5-HEXADIENE)

1960 ◽  
Vol 38 (6) ◽  
pp. 827-834 ◽  
Author(s):  
D. J. Ruzicka ◽  
W. A. Bryce
Keyword(s):  
Activation Energy ◽  
Room Temperature ◽  
Hydrogen Abstraction ◽  
Radical Mechanism ◽  
Static System ◽  
Kcal Mole ◽  
Temperature Range ◽  
Gaseous Products ◽  
Mechanism Of Decomposition ◽  
Liquid Products

The mechanism of decomposition of diallyl has been studied in a static system in the temperature range 460–520 °C. The principal gaseous products (room temperature) were propylene, methane, ethylene, and 1-butene, and the liquid products were cyclopentene, cyclopentadiene, 1-hexene, and benzene. The over-all activation energy of decomposition was 31.3 ± 1.0 kcal/mole for an A factor of 107 sec−1. A mechanism of decomposition based on hydrogen abstraction by allyl and the addition of allyl to olefinic double bonds is proposed. Some decomposition by a non-radical mechanism may also occur.

The kinetics of the reaction between O 2 ( 1 ∆ g ) and ozone

1970 ◽  
Vol 317 (1530) ◽  
pp. 407-416 ◽  
Keyword(s):  
Activation Energy ◽  
Rate Constant ◽  
Room Temperature ◽  
Published Data ◽  
Temperature Range ◽  
A Value ◽  
Kinetics Of

The kinetics of the reaction O 2 ( 1 ∆ g ) + O 3 k 2 → 2O 2 + O have been investigated in the temperature range 195 to 439 K by using the kinetic photo­ionization technique to follow [O 2 ( 1 ∆ g )]. In Arrhenius form, the rate constant, k 2 ,'is given by k 2 = 4.0 ± 1.5 x 10 8 exp (13000 /RT) 1 mol -1 s -1 (joule units) ( = 4.0 ± 1.5 x 10 8 exp (3100/RT) 1 mol -1 s -1 (calorie units)). At room temperature (292 K) k 2 = 2.1 ± 0.3 x 10 6 1 mol -1 s -1 . The activation energy of 13 ± 1.6 kJ mol -1 suggests that there is virtually no barrier to the reaction other than that provided by its endothermicity (12.1 kJ mol -1 ). The results are used to derive, from pre­viously published data, a value of the rate constant for the reaction O + O 3 k 3 → 2O 2 of 4 ± 2 x 10 6 1 mol -1 s -1 at room temperature.

THE VAPOR-PHASE PHOTOLYSIS OF ACETIC ACID

1955 ◽  
Vol 33 (10) ◽  
pp. 1530-1535 ◽  
Author(s):  
P. Ausloos ◽  
E. W. R. Steacie
Keyword(s):  
Activation Energy ◽  
Acetic Acid ◽  
Vapor Phase ◽  
Room Temperature ◽  
Steric Factor ◽  
Primary Process ◽  
Temperature Range ◽  
Abstraction Reaction

The photolysis of acetic acid (CH3COOD) vapor has been investigated in the temperature range from room temperature to 285 °C. Since CH3D formation is independent of temperature, it is certain that the primary process[Formula: see text]occurs to the extent of about 10%. The results are complex and suggest that three other primary processes may occur, viz.[Formula: see text]The abstraction reaction[Formula: see text]is of importance, and the results indicate that it has an activation energy of 10.2 kcal., and a steric factor of the order of 10−3.

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