Kinetic transition in the order–disorder transformation at a solid/liquid interface

Phase-field analysis for the kinetic transition in an ordered crystal structure growing from an undercooled liquid is carried out. The results are interpreted on the basis of analytical and numerical solutions of equations describing the dynamics of the phase field, the long-range order parameter as well as the atomic diffusion within the crystal/liquid interface and in the bulk crystal. As an example, the growth of a binary A 50 B 50 crystal is described, and critical undercoolings at characteristic changes of growth velocity and the long-range order parameter are defined. For rapidly growing crystals, analogies and qualitative differences are found in comparison with known non-equilibrium effects, particularly solute trapping and disorder trapping. The results and model predictions are compared qualitatively with results of the theory of kinetic phase transitions (Chernov 1968 Sov. Phys. JETP 26 , 1182–1190) and with experimental data obtained for rapid dendritic solidification of congruently melting alloy with order–disorder transition (Hartmann et al. 2009 Europhys. Lett. 87 , 40007 ( doi:10.1209/0295-5075/87/40007 )). This article is part of the theme issue ‘From atomistic interfaces to dendritic patterns’.

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The temperature dependence of the long-range order parameter of Ni3Al

Journal of Applied Crystallography ◽

10.1107/s0021889877012709 ◽

1977 ◽

Vol 10 (1) ◽

pp. 14-17 ◽

Cited By ~ 27

Author(s):

D. P. Pope ◽

J. L. Garin

Keyword(s):

Long Range ◽

Order Parameter ◽

Anomalous Behavior ◽

Range Order ◽

Range Order Parameter ◽

Long Range Order ◽

Temperature Range ◽

Ordered Alloys ◽

Fine Particle Size ◽

Increasing Temperature

The macroscopic yield stress of Ni3Al increases rapidly with temperature, reaching a maximum at about 700°C. Such anomalous behavior has been observed in other ordered alloys which undergo partial disordering with increasing temperature, e.g. Cu3Au. The long-range order parameter, S, of stoichiometric Ni3Al powder was measured over the temperature range 25°C to 1000°C and great care was taken to ensure a fine particle size and thus avoid extinction effects. The results of this study showed that, in Ni3Al, S remains constant at about 0.93 over the entire temperature range investigated. This means that theories relating the strength of ordered alloys to S are not applicable to Ni3Al.

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The Effect of Growth Temperature and Substrate Misorientation on Degree of Order and Antiphase Domain Size in Ga0.52In0.48P Epilayers Grown on GaAs (001) Substrates by Gs-Mbe

MRS Proceedings ◽

10.1557/proc-523-235 ◽

1998 ◽

Vol 523 ◽

Cited By ~ 1

Author(s):

C. Meenakarn ◽

A. E. Staton-bevan ◽

S. P. Najda ◽

G. Duggan ◽

A. H. Kean

Keyword(s):

Band Gap ◽

Long Range ◽

Growth Temperature ◽

Order Parameter ◽

Plate Thickness ◽

Antiphase Domain ◽

Range Order ◽

Range Order Parameter ◽

Long Range Order ◽

Gaas Substrates

AbstractA Transmission Electron Microscopy (TEM), Photoluminescence (PL) and Photoluminescence Excitation Spectroscopy (PLE) investigation has been conducted on Ga0.52In0.48P epilayers grown on (001) GaAs substrates by Gas-Source Molecular Beam Epitaxy.For Ga0.52In0.48P epilayers grown on exact (001) GaAs substrates, increasing the growth temperature from 480°C to 535°C increased the antiphase domain plate thickness, t, from 7.3±0.4 to 17.4±0.9 Å, and decreased the long range order parameter, n, from 0.32 to 0.18±0.1. For epilayers grown at 530°C, on GaAs(001) substrates off-cut 0°, 7°, 10° and 15° towards [111]A, increasing the substrate misorientation from 0° to 15° decreased the antiphase domain plate thickness, from 12.3±0.6 to 6.0±0.3 Å. The long range order parameter also decreased from 0.19 to 0.10±0.01.The band gap energies of these samples, grown by GS-MBE, were close to those reported for fully disordered Ga0.52In0.48P epilayers grown by MOCVD at ∼760°C. This shows that GSMBE is also a good technique to grow GaInP for high band gap optical data storage applications and at lower growth temperatures. The optimum growth conditions in this study were at a growth temperature of 530°C on (001) GaAs substrate with 15° off-cut towards [111]A.

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Pb()O3-type Perovskites: Part I. Pair-correlation Theory of Order-disorder Phase Transition

Journal of Materials Research ◽

10.1557/jmr.1997.0284 ◽

1997 ◽

Vol 12 (8) ◽

pp. 2117-2126 ◽

Cited By ~ 11

Author(s):

Hyun M. Jang ◽

Su-Chan Kim

Keyword(s):

Long Range ◽

Order Parameter ◽

Short Range ◽

Short Range Order ◽

Pair Correlation ◽

Range Order ◽

Statistical Thermodynamic ◽

Range Order Parameter ◽

Long Range Order ◽

Short Range Order Parameter

The limitation of the long-range order parameter and the necessity of the short-range order parameter for the thermodynamic description of Pb()O3-type perovskites are discussed. Based on the discussion, a statistical thermodynamic model that takes into account the configuration of the neighboring B-site ions (B′ and B″ cations) was developed. A pair-correlation approximation was used in the calculation of the configurational entropy and the long-range coulombic interaction energy between the nearest B-site ions. The theoretical calculations using Pb(Sc1/2Ta1/2)O3 (PST) and Pb(Sc1/2Nb1/2)O3 (PSN) systems indicate that the short-range order parameter persists over a wide range of temperatures examined (0–1800 K) and that there possibly occur consecutive long-range order-disorder transitions in the configuration of B-site cations. The possibility of the existence of short-range ordering above the long-range order-disorder transition temperature was also examined using the annealed PSN specimen as a typical example of Pb()O3-type perovskites.

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Characterization of the temperature dependence of the long range order parameter in Fe3Pt austenites

Scripta Metallurgica ◽

10.1016/0036-9748(79)90270-9 ◽

1979 ◽

Vol 13 (12) ◽

pp. 1137-1140 ◽

Cited By ~ 5

Author(s):

H. Chang ◽

S. Sastri

Keyword(s):

Temperature Dependence ◽

Long Range ◽

Order Parameter ◽

Range Order ◽

Range Order Parameter ◽

Long Range Order

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Changes in the Bragg-Williams Parameter with Deformation in Ordered Au4V

Advances in X-ray Analysis ◽

10.1154/s0376030800005693 ◽

1968 ◽

Vol 12 ◽

pp. 113-128 ◽

Cited By ~ 1

Author(s):

B. G. LeFevre ◽

E. A. Starke

Keyword(s):

Long Range ◽

Order Parameter ◽

Magnetic Measurements ◽

Cold Deformation ◽

Range Order ◽

Diffraction Spectrum ◽

Range Order Parameter ◽

Long Range Order ◽

Simple Ratio ◽

Integrated Intensities

AbstractThe intermetallic compound Au4V is known to be ferromagnetic at temperatures below 43°K. Its ferromagnetism, which has been attributed to long range order, can he destroyed by cold deformation. The present study was undertaken to determine how the Bragg and Williams long-range-order parameter of the fully-ordered alloy varied as a function of deformation by cold rolling. Because of complexities in the diffraction spectrum it was not possible to determine 5 by a simple ratio of integrated intensities as is frequently done in other ordered systems, A treatment was developed to handle these difficulties using a modification of a method developed by Giamei and Freise for determining volume fractions of mixed phases. These results are correlated with magnetic measurements made by Chin and coworkers at Bell Laboratories.

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