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Critical cooling rate for the glass formation of ferromagnetic Fe40Ni40P14B6 alloy  [PDF]
Qiang Li
Physics , 2006,
Abstract: Bulk ferromagnetic amorphous Fe-Ni-P-B alloys in rod shape were formed by a rapid solidification technique. The largest amorphous specimen prepared had a diameter of ~2.5 mm and the corresponding cooling rate for the glass formation of this alloy system in our experiment can be estimate to be around 492.4 K/s by the method of finite-difference numerical calculation. This value is on the same order of magnitude as the critical cooling rate Rc of Fe40Ni40P14B6 alloy estimated by the method of constructing the continuous-cooling-transformation (CCT) curve. It is indicated that the heterophase impurities have been eliminated well in our experiment.
Spinodal Decomposition of Metastable Melting in the Zero-Temperature Limit  [PDF]
Igor L. Iosilevski,Alexander Yu. Chigvintsev
Physics , 2006,
Abstract: "Conventional" scenario of metastable melting in ordinary substances in the limit of zero temperature assumes that the melting curve reaches the matter zero isotherm ("cold curve"). The same is true for standard variant of one-component plasma model on rigid compensating background in both limits: classical and "cold" quantum melting. The modified OCP on uniform, but compressible background shows the completely different scenario of the metastable melting closure. The remarkable feature of this scenario is that the liquid freezing curve terminates at liquid spinodal curve of 1st-order liquid gas phase transition, which takes place in this type of OCP models ("spinodal decomposition").
Formation of ferromagnetic bulk amorphous Fe40Ni40P14B6 alloys  [PDF]
Qiang Li
Physics , 2006, DOI: 10.1016/j.matlet.2006.02.054
Abstract: Ferromagnetic bulk amorphous Fe40Ni40P14B6 alloy rods with a diameter of 1.2 mm can be prepared by means of a rapid quenching technique. If a fluxing technique is also used, amorphous rods with a diameter as large as 2.5 mm can be synthesized. The critical cooling rate Rc for the glass formation Fe40Ni40P14B6 is estimated to be on the order of 100 K.s-1
Underbarrier nucleation kinetics in a metastable quantum liquid near the spinodal  [PDF]
S. N. Burmistrov,L. B. Dubovskii,Y. Okuda
Physics , 2004, DOI: 10.1103/PhysRevB.71.054512
Abstract: We develop a theory in order to describe the effect of relaxation in a condensed medium upon the quantum decay of a metastable liquid near the spinodal at low temperatures. We find that both the regime and the rate of quantum nucleation strongly depend on the relaxation time and its temperature behavior. The quantum nucleation rate slows down with the decrease of the relaxation time. We also discuss the low temperature experiments on cavitation in normal $^3$He and superfluid $^4$He at negative pressures. It is the sharp distinctions in the high frequency sound mode and in the temperature behavior of the relaxation time that make the quantum cavitation kinetics in $^3$He and $^4$He completely different in kind.
Liquid Limits: The Glass Transition and Liquid-Gas Spinodal Boundaries of Metastable Liquids  [PDF]
Srikanth Sastry
Physics , 2000, DOI: 10.1103/PhysRevLett.85.590
Abstract: The liquid-gas spinodal and the glass transition define ultimate boundaries beyond which substances cannot exist as (stable or metastable) liquids. The relation between these limits is analyzed {\it via} computer simulations of a model liquid. The results obtained indicate that the liquid - gas spinodal and the glass transition lines intersect at a finite temperature, implying a glass - gas mechanical instability locus at low temperatures. The glass transition lines obtained by thermodynamic and dynamic criteria agree very well with each other.
The Glass Transition and Liquid-Gas Spinodal Boundaries of Metastable Liquids  [PDF]
S. S. Ashwin,Gautam I. Menon,Srikanth Sastry
Physics , 2005, DOI: 10.1209/epl/i2006-10194-5
Abstract: A liquid can exist under conditions of thermodynamic stability or metastability within boundaries defined by the liquid-gas spinodal and the glass transition line. The relationship between these boundaries has been investigated previously using computer simulations, the energy landscape formalism, and simplified model calculations. We calculate these stability boundaries semi-analytically for a model glass forming liquid, employing accurate liquid state theory and a first-principles approach to the glass transition. These boundaries intersect at a finite temperature, consistent with previous simulation-based studies.
Spinodal of supercooled polarizable water  [PDF]
P. Gallo,M. Minozzi,M. Rovere
Physics , 2006, DOI: 10.1103/PhysRevE.75.011201
Abstract: We develop a series of molecular dynamics computer simulations of liquid water, performed with a polarizable potential model, to calculate the spinodal line and the curve of maximum density inside the metastable supercooled region. After analysing the structural properties,the liquid spinodal line is followed down to T=210 K. A monotonic decrease is found in the explored region. The curve of maximum density bends on approaching the spinodal line. These results, in agreement with similar studies on non polarizable models of water, are consistent with the existence of a second critical point for water.
Non-equilibrium Characterization of Spinodal Points using Short Time Dynamics  [PDF]
Ernesto S. Loscar,Ezequiel E. Ferrero,Tomas S. Grigera,Sergio A. Cannas
Physics , 2008, DOI: 10.1063/1.3168404
Abstract: Though intuitively appealing, the concept of spinodal is rigourously defined only in systems with infinite range interactions (mean field systems). In short-range systems, a pseudo-spinodal can be defined by extrapolation of metastable measurements, but the point itself is not reachable because it lies beyond the metastability limit. In this work we show that a sensible definition of spinodal points can be obtained through the short time dynamical behavior of the system deep inside the metastable phase, by looking for a point where the system shows critical behavior. We show that spinodal points obtained by this method agree both with the thermodynamical spinodal point in mean field systems and with the pseudo-spinodal point obtained by extrapolation of meta-equilibrium behavior in short range systems. With this definition, a practical determination can be achieved without regard for equilibration issues.
Coherent terahertz needle radiation emission mechanism from nanostructured ferromagnetic metal films excited by femtosecond laser pulses  [PDF]
Anatoly D. Gladun,Vladimir G. Leiman,Aleksey V. Arsenin
Physics , 2008,
Abstract: A coherent terahertz needle radiation emission mechanism is proposed. This mechanism can be realized in the experiments on femtosecond laser pulses interacting with surface of nanostructured ferromagnetic metal film. The proposed mechanism is based on exciting of coupled coherent phonon-magnon modes on a nanostructured metal surface by laser femtosecond pulse. The value of the Poynting vector for the terahertz radiation is estimated.
Effects of elastic energy on the spinodal decomposition of InNAsP/InP heterostructures
Díaz Albarrán, S.F.;Elyukhin, V.A.;Peralta, P.R;
Revista mexicana de física , 2011,
Abstract: spinodal decomposition of the innxasyp1-x-y quaternary alloys lattice-matched to the inp as the result of the internal deformation and elastic energies is described. the alloys are represented as quasiternary regular solutions. the internal deformation energy is obtained from the interaction parameters between the constituent compounds estimated by the valence force field model. ranges of spinodal decomposition of the innxasyp1-x-y alloys up to y ≤ 0.109 with and without elastic energy are demonstrated. our results suggest that such energy prevents spinodal decomposition.
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