scholarly journals Theory of Inhomogeneous Short Range Order and Calphad Modeling. Part 6. Order-Disorder Transformations in Alloys

2020 ◽  
Author(s):  
Edward Kremer
Keyword(s):  
Long Range ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
Long Range Order ◽  
Calphad Modeling ◽  
Solid Alloys

Formalism of Theory of Inhomogeneous Short Range Order (TISR) is extendedto describe Order–Disorder transformations in solid alloys. The result is a naturalintegration of Short and Long Range Order description in the framework of thesame theory.The equations of Cluster Site Approximation (CSA) are deduced directly fromthe equations of TISR. Formalism and interpretation of CSA are simplified andclarified.

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

1997 ◽  
Vol 12 (8) ◽  
pp. 2117-2126 ◽  
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.

Short range order and its transformation to long range order in Ni4Mo

1998 ◽  
Vol 46 (3) ◽  
pp. 881-892 ◽  
Author(s):  
Satoshi Hata ◽  
Syo Matsumura ◽  
Noriyuki Kuwano ◽  
Kensuke Oki
Keyword(s):  
Long Range ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
Long Range Order

Short‐Range Order Coexisting with Long‐Range Order in Cu3Au

1956 ◽  
Vol 27 (3) ◽  
pp. 203-206 ◽  
Author(s):  
B. W. Roberts ◽  
G. H. Vineyard
Keyword(s):  
Long Range ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
Long Range Order

Order-disorder in 1:1 type clay minerals by solid-state 27Al and 29Si magic-angle-spinning NMR spectroscopy

Clay Minerals ◽  
1985 ◽  
Vol 20 (3) ◽  
pp. 327-334 ◽  
Author(s):  
S. Komarneni ◽  
C. A. Fyfe ◽  
G. J. Kennedy
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Long Range ◽  
Short Range ◽  
Short Range Order ◽  
Magic Angle Spinning ◽  
Range Order ◽  
Magic Angle ◽  
Long Range Order ◽  
Tetrahedral Coordination ◽  
Angle Spinning

AbstractThe applicability of 27Al and 29Si magic-angle-spinning nuclear magnetic resonance (MASNMR) spectroscopy to the investigation of order-disorder in 1 : 1 dioctahedral layer-silicates was tested. 27Al and 29Si MASNMR showed the existence of short-range order in all these systems while XRD showed different degrees of long-range order-disorder. Spectra obtained on kaolinite and metakaolin clearly showed the transformation of some octahedral Al in kaolinite to tetrahedral coordination in metakaolin and also showed short-range Al and Si disorder in the latter. This suggests that structural re-arrangement on thermal treatment can be monitored by this technique. These results further suggest that MASNMR can detect short-range order, which is complimentary to the information that XRD provides regarding long-range order.

Short range order and the development of long range order in Ni4Mo

1974 ◽  
Vol 35 (9) ◽  
pp. 1317-1326 ◽  
Author(s):  
B. Chakravarti ◽  
E.A. Starke ◽  
C.J. Sparks ◽  
R.O. Williams
Keyword(s):  
Long Range ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
Long Range Order
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