Correlation Between Resistivity Characteristics and Electronic Structure Parameters of the Ni-Pd-P Amorphous Alloys

2000 ◽  
Vol 644 ◽  
Author(s):  
Mykola Babich ◽  
Olesya Nakonechna ◽  
Mykhailo Semen'ko ◽  
Mykola Zakharenko ◽  
Gennagy Yeremenko ◽  
...  
Keyword(s):  
Amorphous Alloys ◽  
Crystallization Process ◽  
Level Shift ◽  
Relaxation Processes ◽  
Temperature Range ◽  
Temperature Coefficients ◽  
Localized State ◽  
P Content ◽  
Two Stages ◽  
Kinetics Of

AbstractThe temperature dependencies of resistivity of the Ni-Pd-P-based amorphous alloys (P content was varied from 14 to 23 at. %) have been measured in a wide temperature range using the standard four-probe method. The temperature coefficients of resistivity (TCR) have been calculated. TCR value is decreased with P content increasing and becomes negative for Ni46Pd31P23 alloy. On the other hand, TCR value is increased with Pd content increasing while P content is not changed. Such behavior could be attributed to the electronic transfer effect from Ni to Pd and from P to Ni. These lead to the Fermi level shift to d-band edge and to the increasing influence of the Mott's localized state. The peculiarities caused by structural relaxation processes have been observed at the temperature range of 550 – 620 K. The relaxation process was shown to consist at least of two stages. The kinetics of the crystallization process has been analyzed using the Kissinger method.

Crystallization process and kinetics of SmCo/Fe and SmCo/FeCo partially crystallized amorphous alloys

2016 ◽  
Vol 432 ◽  
pp. 361-365 ◽  
Author(s):  
Qian Zhang ◽  
Wenpeng Song ◽  
Guangwei Huang ◽  
Li Lou ◽  
Fuchen Hou ◽  
...  
Keyword(s):  
Amorphous Alloys ◽  
Crystallization Process ◽  
Kinetics Of

KINETICS OF ADSORPTION OF ORGANIC AND INORGANIC PHOSPHATES BY SHORT-RANGE ORDERED PRECIPITATE OF ALUMINUM

1990 ◽  
Vol 70 (3) ◽  
pp. 461-470 ◽  
Author(s):  
C. SHANG ◽  
P. M. HUANG ◽  
J. W. B. STEWART
Keyword(s):  
Short Range ◽  
Kinetics Of Adsorption ◽  
Temperature Range ◽  
First Order Kinetics ◽  
Initial Ph ◽  
Two Stages ◽  
Relationship Of ◽  
Kinetics Of ◽  
Inorganic Phosphates ◽  
Phosphate Groups

The kinetics of the adsorption of orthophosphate (Pi), inositol hexaphosphate (IHP), inositol monophosphate (IMP) and glucose 6-phosphate (G6P) by short-range ordered precipitate of Al were studied at the initial pH 4.50 and in the temperature range of 278–308 K. This information is essential for understanding the rate and energy relationship of the adsorption of phosphates by short-range ordered Al precipitate. The amounts of Pi and IHP adsorbed by the Al precipitate were much higher than those of IMP and G6P adsorbed in the temperature range and reaction periods studied. The adsorption can be divided into two stages, a fast adsorption before 1 h and a slow adsorption between 1 and 24 h. The adsorption at both stages obeyed the first-order kinetics. Among all the phosphates studied, the adsorption of Pi proceeded most rapidly. The rate constants for the adsorption of IHP were much greater than those of G6P and IMP at the same temperature; this was attributed to the functionality of multiple phosphate groups of IHP. The Arrhenius activation energies for the adsorption of Pi, IHP, IMP and G6P, which were estimated from the slow reaction, were 48 ± 2, 89 ± 4, 100 ± 8 and 108 ± 10 KJ/mol P adsorbed, respectively. Key words: Organic phosphate, precipitate of aluminum, adsorption, rate constant, Arrhenius activation energy

Kinetics of Relaxation at the Liquid-Glass Transition

1990 ◽  
Vol 205 ◽  
Author(s):  
Laurent J. Lewis
Keyword(s):  
Glass Transition ◽  
Liquid Glass ◽  
Realistic Model ◽  
Relaxation Mechanism ◽  
Relaxation Processes ◽  
Conformational Relaxation ◽  
Atomic Transport ◽  
Dynamics Simulations ◽  
Two Stages ◽  
Kinetics Of

AbstractWe use molecular-dynamics simulations to investigate relaxation processes near the liquid-glass transition for a realistic model of the metal-metalloid system Ni80P20. We find that relaxation proceeds in two stages, excluding phonons: fast (or conformational) relaxation, related to local rearrangements of atoms, and slow relaxation, connected with atomic transport, i.e. diffusion. These processes are usually referred to as β and α, respectively. Our simulations show that diffusion exists even in the glass state, where it proceeds mostly by jumps, in contrast to the liquid phase where it is continuous. This relaxation mechanism is well described by a stretched exponential (Kohlrausch) law, in accord with recent modecoupling theories for supercooled liquids. The fast relaxation regime, on the other hand, does not appear to be well described by the theory.

Nanocrystallization Kinetics of Amorphous Fe-Based Multicomponent Alloy by Non-Isothermal Analysis

2008 ◽  
Vol 570 ◽  
pp. 109-113
Author(s):  
T. Lilly Shanker Rao ◽  
Kirit N. Lad ◽  
Heena Dhurandhar ◽  
Arun Pratap ◽  
Prafulla K. Jha
Keyword(s):  
Metallic Glasses ◽  
Amorphous Alloys ◽  
Crystallization Process ◽  
Primary Crystallization ◽  
Soft Magnetic ◽  
Soft Magnetic Alloys ◽  
Dsc Measurements ◽  
Isothermal Analysis ◽  
Kinetics Of ◽  
Mechanism Of Growth

Soft magnetic alloys consisting of nanoscale fcc Fe grains have been developed by primary crystallization of melt-spun amorphous alloys as typically exemplified in Fe-B[1], Fe-M-B (M = Zr, Hf, Nb) (Nanoperm) [2] and Fe-Si-B-Nb-Cu (FINEMET)systems[3]. Lot of scientific effort has been put in last years to control the crystallization process of metallic glasses. This is due to the fact that several attractive properties of the resulting material are strongly related to the final attained microstructure. In the present paper, primary nanocrystallization kinetics of a Fe–based multicomponent amorphous system namely Fe67Co18B14Si1 (2605CO) has been analysed by nonisothermal DSC measurements. Crystallization is a combined process of nucleation and growth. The amorphous alloy undergoes two-step crystallization with primary crystallization of α-Fe giving the first step. The Avrami exponent for the two steps has been derived. A detailed analysis of the data provides an insight in to the dimensionality and mechanism of growth.

scholarly journals Влияние редкоземельных металлов на стеклообразующую способность и кристаллизацию аморфных сплавов CoFeSiBNb

2022 ◽  
Vol 92 (1) ◽  
pp. 58
Author(s):  
Б.А. Русанов ◽  
В.Е. Сидоров ◽  
P. Svec ◽  
D. Janickovic ◽  
В.И. Ладьянов ◽  
...  
Keyword(s):  
Amorphous Alloys ◽  
Crystallization Process ◽  
A Priori ◽  
Glass Forming Ability ◽  
Analysis Method ◽  
Thermal Analysis Method ◽  
Glass Forming ◽  
Planar Flow Casting ◽  
Rare Earth Addition ◽  
Two Stages

In present work amorphous alloys Co48Fe25Si4B19Nb4-R (R = Nd, Sm, Tb, Yb) were obtained by planar flow casting in the form of ribbons with 3-5 mm wide and 35-45 μm thickness. It was found that crystallization process goes into two stages and depends on the used rare-earth addition and its content in the alloy by differential thermal analysis method. Glass-forming ability criteria were calculated. It is shown that paramagnetic Curie temperature of alloys in liquid state can be used as their a-priori criterion of glass-forming ability.

Thermal Stability and Relaxation Processes of The Ti-Cu- and Ti-Ni-Based Metallic Glasses

1993 ◽  
Vol 321 ◽  
Author(s):  
Nikolay G. Babich ◽  
Nikolay N. Dashevsky ◽  
Olesja I. Nakonechna ◽  
Sergey L. Revo ◽  
Nikolay I. Zakharenko
Keyword(s):  
Thermal Stability ◽  
Magnetic Susceptibility ◽  
Metallic Glasses ◽  
Amorphous Alloys ◽  
Relaxation Processes ◽  
Spin Moment ◽  
Temperature Range ◽  
Impurity Atoms ◽  
Temperature Dependences ◽  
Thermal Stability Of

ABSTRACTTemperature dependences of magnetic susceptibility for Ti-Cu- and Ti-Ni-based amorphous alloys have been obtained in the temperature range 300–850 K. All investigated alloys are shown to be Pauli paramagnets. Fe and Co impurity atoms possess zero localized moment due to effect of spin moment quenching. Relaxation processes were studied using thermopower measurements. It was shown the thermal stability of investigated alloys is determined predominantly by Nagel-Tauc electronic criterion.

Kinetics of Structural Relaxation in Metal Glasses

1995 ◽  
Vol 398 ◽  
Author(s):  
O.I. Nakonechna ◽  
N.I. Zakharenko ◽  
V.S. Kopan ◽  
N.N. Dashevsky ◽  
N.G. Babich
Keyword(s):  
Transition Metal ◽  
Structural Relaxation ◽  
Amorphous Alloys ◽  
Relaxation Processes ◽  
Atom Migration ◽  
Kinetics Of ◽  
Metal Glasses

ABSTRACTRelaxation processes in different amorphous transition metal-metalloid (TM-M)-type alloys have been studied using thermopower measurements. The migration of two types of atomic complexes has been considered. For Ti-based amorphous alloys the migration of TM atoms and TM-M complexes diffusion are at least two processes that define the structural relaxation. For Ni and Fe-based alloys the relaxation processes are determined first of all by isolated TM atom migration.

Features of radiothermoluminescence of polypropylene and ethylene propylenediene elastomer SKEPT-4044 compositions with nanoscale metal-containing fillers

2020 ◽  
pp. 66-73
Author(s):  
A.M. Magerramov ◽  
◽  
N.I. Kurbanova ◽  
M.N. Bayramov ◽  
N.A. Alimirzoyeva ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Molecular Mobility ◽  
Fe3o4 Nanoparticles ◽  
Low Temperatures ◽  
Frost Resistance ◽  
Relaxation Processes ◽  
Ethylene Propylene ◽  
Temperature Range ◽  
Β Relaxation

Using radiothermoluminescence (RTL), the molecular mobility features in the temperature range of 77-300 K were studied for the polypropylene (PP)/ethylene propylene diene elastomer SKEPT-4044 with NiO, Cu2O and Fe3O4 nanoparticles (NPs) based on ABS-acrylonitrile butadiene or SCS-divinyl styrene matrices. It has been shown that the introduction of nanofillers in PP significantly affects the nature and temperature of γ- and β-relaxation processes, while the region of manifestation of the β-process noticeably shifts to the region of low temperatures. Composites with Cu2O NPs have a higher β-transition temperature Tβ than composites with other NPs. It was found that PP/SKEPT-4044 composites with Cu2O NPs with a dispersion of 11-15 nm and acrylonitrile butadiene thermoplastics have optimal frost resistance compared to other compositions.

Initiation of the Explosive Crystallization Process in Amorphous Alloys of the Fe-Zr System by Pulse Laser Treatment

2019 ◽  
Vol 11 (2) ◽  
pp. 02004-1-02004-5
Author(s):  
T. L. Tsaregradskaya ◽  
◽  
Yu. A. Kunitskyi ◽  
О. О. Kаlenyk ◽  
I. V. Plyushchay ◽  
...  
Keyword(s):  
Laser Treatment ◽  
Pulse Laser ◽  
Amorphous Alloys ◽  
Crystallization Process ◽  
Explosive Crystallization

scholarly journals Non-Isothermal Crystallization Kinetics of Poly(Ethylene Glycol)–Poly(l-Lactide) Diblock Copolymer and Poly(Ethylene Glycol) Homopolymer via Fast-Scan Chip-Calorimeter

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1156
Author(s):  
Dejia Chen ◽  
Lisha Lei ◽  
Meishuai Zou ◽  
Xiaodong Li
Keyword(s):  
Ethylene Glycol ◽  
Heterogeneous Nucleation ◽  
Isothermal Crystallization ◽  
Crystallization Process ◽  
Poly Ethylene Glycol ◽  
Ozawa Method ◽  
Isothermal Crystallization Kinetics ◽  
Fast Cooling ◽  
Poly Ethylene ◽  
Kinetics Of

The non-isothermal crystallization kinetics of double-crystallizable poly(ethylene glycol)–poly(l-lactide) diblock copolymer (PEG-PLLA) and poly(ethylene glycol) homopolymer (PEG) were studied using the fast cooling rate provided by a Fast-Scan Chip-Calorimeter (FSC). The experimental data were analyzed by the Ozawa method and the Kissinger equation. Additionally, the total crystallization rate was represented by crystallization half time t1/2. The Ozawa method is a perfect success because secondary crystallization is inhibited by using fast cooling rate. The first crystallized PLLA block provides nucleation sites for the crystallization of PEG block and thus promotes the crystallization of the PEG block, which can be regarded as heterogeneous nucleation to a certain extent, while the method of the PEG block and PLLA block crystallized together corresponds to a one-dimensional growth, which reflects that there is a certain separation between the crystallization regions of the PLLA block and PEG block. Although crystallization of the PLLA block provides heterogeneous nucleation conditions for PEG block to a certain extent, it does not shorten the time of the whole crystallization process because of the complexity of the whole crystallization process including nucleation and growth.

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