Interfacial reactions in multilayers intended for microelectronics devices

1998 ◽  
Vol 514 ◽  
Author(s):  
X. Federspiel ◽  
F. Voiron ◽  
M. Ignat ◽  
T. Marieb ◽  
H. Fujimoto
Keyword(s):  
Phase Formation ◽  
Reaction Rate ◽  
Experimental Approach ◽  
Intermetallic Phase ◽  
Activation Energies ◽  
Interfacial Reactions ◽  
Scanning Calorimetry ◽  
Back Scattering ◽  
Apparent Activation Energies ◽  
Kinetics Of

ABSTRACTThe knowledge of the reaction kinetics which can occur at an interface of a couple of materials, remains a crucial issue to establish the structural limits of a diffusion barrier intended for microelectronic structures.In the past years, the interfacial reactions activated at an interface of a couple of materials, as for example aluminum and titanium, have been analyzed extensively using different experimental tools, as for example: Ruthreford Back Scattering (thickness determination) and Differential Scanning Calorimetry (DSC). Then, these experimental methods were useful to deduce parameters, characterizing the interfacial reactions in bulk samples: apparent activation energies, enthalpy of formation. Because in thin films, the kinetics of the reactions that can be activated at an interface will be different; we studied interfacial reactions in submicronic Al/Ti layers.Taking advantage of the accuracy of the DSC (reaction rate determinations and detection of earlier stages of intermetallic phase formation), our experimental approach consisted in a series of isothermal and non-isothermal DSC experiments on submicron Al/Ti layered structures. From the reaction rate determination, analytical methods as the Kissinger Ozawa approach were used, to determine the apparent activation energies of the phase formation. Also the results allowed to model and discuss the first steps of the interfacial reaction.

A Model for Formation and Consumption of Transient Phase

2011 ◽  
Vol 172-174 ◽  
pp. 646-651 ◽  
Author(s):  
Gamra Tellouche ◽  
Khalid Hoummada ◽  
Dominique Mangelinck ◽  
Ivan Blum
Keyword(s):  
Differential Scanning Calorimetry ◽  
Phase Formation ◽  
Transient Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Proposed Model ◽  
Transient Phases ◽  
Kinetics Of

The phase formation sequence of Ni silicide for different thicknesses is studied by in situ X ray diffraction and differential scanning calorimetry measurements. The formation of a transient phase is observed during the formation of δ-Ni2Si; transient phases grow and disappear during the growth of another phase. A possible mechanism is proposed for the transient phase formation and consumption. It is applied to the growth and consumption of θ-Ni2Si. A good accordance is found between the proposed model and in situ measurement of the kinetics of phase formation obtained by x-ray diffraction and differential scanning calorimetry for higher thickness.

Glass transformation in vitreous As2Se3 studied by conventional and temperature-modulated differential scanning calorimetry

2001 ◽  
Vol 16 (8) ◽  
pp. 2399-2407 ◽  
Author(s):  
S. O. Kasap ◽  
D. Tonchev
Keyword(s):  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Relaxation Time ◽  
Glass Transition ◽  
Activation Energies ◽  
Temperature Modulation ◽  
Glass Transition Region ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Apparent Activation Energies

We have studied the glass transition behavior of vitreous As2Se3 by carrying out temperature-modulated differential scanning calorimetry (TMDSC) and conventional differential scanning calorimetry (DSC) experiments to measure the glass transition temperature Tg. In TMDSC experiments we have examined the reversing heat flow (RHF), that is the complex heat capacity CP in the glass transition region as the glass is cooled from a temperature above the glass transition temperature (from a liquidlike state) and also as the glass is heated starting from room temperature (from a solidlike state). The RHF, or CP versus T, in TMDSC changes sigmoidally through the glass transition region without evincing an enthalpic peak which is one of its distinct advantages for studying the glass transformations. The Tg measurements by TMDSC were unaffected by the amplitude of the temperature modulation. We have determined apparent activation energies by using Tg-shift methods based on the Tg-shift with the frequency (ω) of temperature modulation in the TMDSC mode and Tg-shift with heating and cooling rates, r and q, respectively, in the DSC mode. It is shown that the apparent activation energies ∆h* obtained from ln ω versus 1/Tg and ln q versus 1/Tg plots are not the same, but nonetheless, they are approximately the same as the apparent activation energy ∆hn of the viscosity over the same temperature range where the empirical Vogel expression of Henderson and Ast, η = 12.9 exp[2940/(T - 335)], was used for the viscosity. The latter observation is in agreement with the assertion that the structural relaxation time Ʈ is proportional to the viscosity h. The apparent activation energy ∆hr obtained from the ln r versus 1/Tg plot during heating DSC scans is lower than ∆h* observed during cooling scans. The results are discussed in terms of a phenomenological Narayanaswamy type relaxation time. It was observed that Tg obtained from TMDSC cooling experiments did not depend on the underlying cooling rate for q ≤ 1 °C min-1; and for temperature amplitudes 0.5–5 °C. The transition due to the temperature modulation was well separated from the transition due to the underlying cooling rate. Further, the apparent activation energies obtained from ln ω versus 1/Tg during cooling and heating scans for q and r ≤ 1 °C min−1 are approximately the same as expected from Hutchison's calculations using a single relaxation time model of TMDSC experiments.

SOĞUK HADDELENMİŞ AA3105 VE AA5005 LEVHALARIN DSC ANALİZİ İLE YENİDEN KRİSTALLENME KİNETİĞİ

2021 ◽  
Vol 8 (17) ◽  
pp. 80-85
Author(s):  
Atae RAOUGUI ◽  
Ion GRECU ◽  
Volkan Murat YILMAZ ◽  
Kenan YILDIZ
Keyword(s):  
Differential Scanning Calorimetry ◽  
Aluminum Alloy ◽  
Activation Energies ◽  
Isothermal Kinetics ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Recrystallization Kinetics ◽  
Model Free ◽  
Cold Rolled ◽  
Kinetics Of

In this study, the non-isothermal recrystallization kinetics of cold rolled AA3105 and AA5005 aluminum alloy sheets obtained from ASAŞ Aluminum located in Akyazı-Sakarya was studied by using differential scanning calorimetry (DSC). The non – isothermal kinetics was performed by using Kissenger, Boswell, Ozawa and Starink methods known as model – free methods. The recrystallization temperatures on DSC graphics at different heating rates (β) were deduced and the activation energies were calculated from the slopes from Y – 1/T diagrams. Y is ln(β/T2) for Kissenger, ln(β/T) for Boswell, ln(β) for Ozawa and ln(β/T1.92) for Starink. The results showed that the activation energies of recrystallization are in the range of 194 – 206 kJ/mol for cold rolled AA5005 sheet and in the range of 235 – 257 kJ/mol for cold rolled AA3105 sheet, according to four non-isothermal kinetics model.

Non-isothermal Cure Kinetics of Polybenzoxazine/Carbon Fiber Composites by Phase Change Theory

2005 ◽  
Vol 13 (6) ◽  
pp. 599-605
Author(s):  
Chunling Xin ◽  
Xiaoping Yang ◽  
Dingsheng Yu
Keyword(s):  
Carbon Fiber ◽  
Marked Change ◽  
Activation Energies ◽  
Curing Temperature ◽  
Avrami Equation ◽  
Published Data ◽  
Carbon Fiber Composites ◽  
Scanning Calorimetry ◽  
Cure Reaction ◽  
Apparent Activation Energies

The cure of benzoxazines (BA-a) and benzoxazine/carbon fiber (BA-a/CF) composites was monitored by non-isothermal differential scanning calorimetry (DSC) at various heating rates. The characteristic temperatures of BA-a and BA-a/CF were analysed. The results showed that the initial cure temperature of BA-a/CF was lower than that of BA-a at the same heating rate. Various kinetic parameters and apparent activation energies for both curing systems were obtained by using a modified version of the Avrami equation. For BA-a, the apparent activation energy was 116.8 kJ/mol, which agreed well with the published data. For BA-a/CF, the results showed that the plot of Avrami rate constant vs. 1/T was not a straight line for the whole curing temperature range, but it displayed a marked change in slope at around 220 oC. The apparent activation energies at primary and second section were 105.6 kJ/mol and 224.8 kJ/mol respectively. The cure reaction of benzoxazines was not only catalysed by carbon fiber, but also was retarded by it.

Modeling Reaction Kinetics of Twin Polymerization via Differential Scanning Calorimetry

2018 ◽  
Vol 43 (4) ◽  
pp. 347-357
Author(s):  
Janett Prehl ◽  
Robin Masser ◽  
Peter Salamon ◽  
Karl Heinz Hoffmann
Keyword(s):  
Reaction Mechanism ◽  
Density Functional ◽  
Reaction Rate ◽  
Density Functional Theory Calculations ◽  
Scanning Calorimetry ◽  
Functional Theory ◽  
Reaction Rate Constants ◽  
Acid Catalyzed ◽  
Kinetics Of ◽  
Derivatives Of

Abstract We present a kinetic model for the reaction mechanism of acid-catalyzed twin polymerization. Our model characterizes the reaction mechanism not by the reactants, intermediate structures, and products, but via reaction-relevant moieties. We apply our model for three different derivatives of 2,2’-Spirobi[4H-1,3,2-benzodioxasiline] and determine activation energies, reaction enthalpies, and reaction rate constants for the reaction steps in our mechanism. We compare our findings to previously reported values obtained from density functional theory calculations. Furthermore, with this approach we are also able to follow the time development of the concentrations of the reaction-relevant moieties.

scholarly journals Kinetics of the catalytic cracking of naphtha over ZSM-5 zeolite: effect of reduced crystal size on the reaction of naphthenes

2014 ◽  
Vol 4 (12) ◽  
pp. 4265-4273 ◽  
Author(s):  
Hiroki Konno ◽  
Ryota Ohnaka ◽  
Jun-ichi Nishimura ◽  
Teruoki Tago ◽  
Yuta Nakasaka ◽  
...  
Keyword(s):  
Rate Constants ◽  
Atmospheric Pressure ◽  
Catalytic Cracking ◽  
Reaction Rate ◽  
Crystal Size ◽  
Activation Energies ◽  
Reaction Rate Constants ◽  
Kinetics Of

The catalytic cracking of model naphthenes over ZSM-5 zeolites of different crystal sizes was examined at reaction temperatures ranging from 748 to 923 K under atmospheric pressure, focusing on the associated reaction rate constants and activation energies.

scholarly journals Sustainable Valorization of Animal Manure and Recycled Polyester: Co-pyrolysis Synergy

2019 ◽  
Vol 11 (8) ◽  
pp. 2280 ◽  
Author(s):  
Zuhal Akyürek
Keyword(s):  
Room Temperature ◽  
Animal Manure ◽  
Activation Energies ◽  
Cattle Manure ◽  
Synergistic Interactions ◽  
Kinetics Of Decomposition ◽  
Single Region ◽  
Fwo Method ◽  
Apparent Activation Energies ◽  
Kinetics Of

In this study sustainable valorization of cattle manure, recycled polyester, and their blend (1:1 wt.%) were examined by the thermogravimetric analysis (TGA) method. Pyrolysis tests were performed at 10, 30, and 50 °C/min heating rate from room temperature to 1000 °C under a nitrogen environment with a flow of 100 cm3/min. Kinetics of decomposition were analyzed by using Flynn–Wall–Ozawa (FWO) method. Based on activation energies and conversion points, a single region was established for recycled polyester while three regions of pyrolysis were obtained for cattle manure and their blend. Comparison between experimental and theoretical profiles indicated synergistic interactions during co-pyrolysis in the high temperature region. The apparent activation energies calculated by FWO method for cattle manure, recycled polyester. and their blend were 194.62, 254.22 and 227.21 kJ/mol, respectively. Kinetics and thermodynamic parameters, including E, ΔH, ΔG, and ΔS, have shown that cattle manure and recycled polyester blend is a remarkable feedstock for bioenergy.

ANIONIC POLYMERIZATION OF STYRENE

1960 ◽  
Vol 38 (10) ◽  
pp. 1891-1900 ◽  
Author(s):  
D. J. Worsfold ◽  
S. Bywater
Keyword(s):  
Absorption Spectra ◽  
Anionic Polymerization ◽  
Benzene Solution ◽  
Activation Energies ◽  
Ultraviolet Absorption ◽  
First Order ◽  
Initiation And Propagation ◽  
Apparent Activation Energies ◽  
Kinetics Of

A study of the kinetics of the initiation and propagation reactions in the polymerization of styrene by butyllithium in benzene solution has been made. The initiation has been shown to be first order in styrene and 0.155 order in butyllithium, the propagation to be first order in styrene and half order with respect to active chain ends. The apparent activation energies of the two reactions have been shown to be 18,000 calories and 14,300 calories respectively. The ultraviolet absorption spectra of colored species produced has been measured and compared with others found in similar systems.

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