Isothermal Evolution of Long Range Order in Bulk Metallic Glass Ni15Pt60P25near Glass Transition: In-Situ SANS Measurement

1997 ◽  
Vol 126 ◽  
pp. 75-78 ◽  
Author(s):  
Kaoru Shibata ◽  
Takeshi Higuchi ◽  
An-Pang Tsai ◽  
Masayuki Imai ◽  
Kenji Suzuki
Keyword(s):  
Glass Transition ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Long Range ◽  
Range Order ◽  
Long Range Order

TRANSITION FROM SHORT-RANGE TO LONG-RANGE ORDER IN LEAD-BISMUTHATE OXIDE GLASS MATRICES

2000 ◽  
Vol 14 (29) ◽  
pp. 1025-1031 ◽  
Author(s):  
V. SIMON ◽  
R. POP ◽  
S. SIMON
Keyword(s):  
Glass Transition ◽  
Molar Volume ◽  
Long Range ◽  
Short Range ◽  
Structural Changes ◽  
Range Order ◽  
Oxide Glass ◽  
Compositional Variation ◽  
Long Range Order ◽  
Glass Matrices

Glass transition and nucleation temperatures as well as densities and molar volumes of x Bi 2 O 3·y PbO (0.5≤x/y≤4) are reported. The glass transition temperature and molar volume are further analysed in terms of structural data. The obtained results indicate the occurrence of structural changes from short range to long range order induced by the heat treatment applied at 550°C, as per DTA results. These changes depend on the x/y ratio between Bi 2 O 3 and PbO content. The compositional variation of the molar volume of untreated and heat-treated samples are evidences that both Bi 2 O 3 and PbO play the role of network formers.

Emergence of Quasi-Long-Range Order below the Bragg Glass Transition

2007 ◽  
Vol 99 (14) ◽  
Author(s):  
N. D. Daniilidis ◽  
S. R. Park ◽  
I. K. Dimitrov ◽  
J. W. Lynn ◽  
X. S. Ling
Keyword(s):  
Glass Transition ◽  
Long Range ◽  
Range Order ◽  
Long Range Order ◽  
Bragg Glass

Effect of Compositional Short Range Order on Glass Formation in Binary Metallic System

2002 ◽  
Vol 754 ◽  
Author(s):  
Hao Chen ◽  
Mahadevan Khantha ◽  
Takeshi Egami
Keyword(s):  
Glass Transition ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Glass Formation ◽  
Short Range ◽  
Short Range Order ◽  
Glass Forming Ability ◽  
Range Order ◽  
Dynamics Simulation ◽  
Glass Forming

ABSTRACTMolecular Dynamics simulation was carried out to study the glass transition and crystallization in the metal-metalloid binary system with pair-wise potentials. The results show that a repulsive potential between metalloid (small) atoms increases the glass forming ability. The observation is consistent with the recent theory of bulk metallic glass formation through local glass transition and nano-glass formation. The theory predicted that the compositional short-range order (CSRO) prevents the small atom pairing so as to increase the glass forming ability (GFA). The present results demonstrate the important role of CSRO in bulk metallic glass formation.

scholarly journals Influence of In-Situ Nanoprecipitation on Constant Load Deformation in the Glass Transition Region of a Cu60Zr30Ti10 Bulk Metallic Glass

2004 ◽  
Vol 45 (7) ◽  
pp. 2383-2388
Author(s):  
Hidemi Kato ◽  
Dmitri V. Louzguine ◽  
Akihisa Inoue ◽  
Hyoung Seop Kim ◽  
Ho-Sou Chen
Keyword(s):  
Glass Transition ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Transition Region ◽  
Constant Load ◽  
Glass Transition Region

LONG RANGE ORDER IN ULTRATHIN Pt–Co(111) ALLOYS

1999 ◽  
Vol 06 (03n04) ◽  
pp. 361-368 ◽  
Author(s):  
M. DE SANTIS ◽  
R. BAUDOING-SAVOIS ◽  
P. DOLLE ◽  
M. C. SAINT-LAGER ◽  
Y. GAUTHIER
Keyword(s):  
Long Range ◽  
Range Order ◽  
Anomalous Scattering ◽  
Long Range Order ◽  
X Ray Diffraction ◽  
Rich Alloy ◽  
Atomic Scattering ◽  
Fcc Alloys ◽  
The Relationship

Long range order (LRO) in ultrathin Pt–Co films was studied by surface X-ray diffraction (XRD). Several fcc alloys of nanometric thickness were grown in situ by annealing at 460°C Co layers deposited onto a Pt(111) single crystal. Superstructure reflections were observed, which agreed with the extinction rules of either the L1 2 or the L1 0 chemically ordered bulk phases. The relationship between their structure factor and the atomic scattering factors was found with anomalous scattering performed near both Pt L III and Co K edges. This method is very promising for studies of surface alloying. The films were also studied in real time during annealing. They evolved in a quite different way, depending on the initial Co thickness, but LRO always occurred by heating above 400°C. At this temperature the films became Pt-rich, with a stoichiometry close to Pt 60 Co 40. We did not succeed in obtaining long range chemical order in a Co-rich alloy by annealing a Co/Pt(111) deposit, contrary to what happens in films grown by codeposition.

Superfluidity and Superconductivity

2018 ◽  
Author(s):  
Norman J. Morgenstern Horing
Keyword(s):  
Magnetic Field ◽  
Wave Function ◽  
Wave Packet ◽  
Long Range ◽  
Cooper Pair ◽  
Bose Condensation ◽  
Range Order ◽  
Condensed State ◽  
Long Range Order ◽  
Coherent Wave

Chapter 13 addresses Bose condensation in superfluids (and superconductors), which involves the field operator ψ‎ having a c-number component (<ψ(x,t)>≠0), challenging number conservation. The nonlinear Gross-Pitaevskii equation is derived for this condensate wave function<ψ>=ψ−ψ˜, facilitating identification of the coherence length and the core region of vortex motion. The noncondensate Green’s function G˜1(1,1′)=−i<(ψ˜(1)ψ˜+(1′))+> and the nonvanishing anomalous correlation function F˜∗(2,1′)=−i<(ψ˜+(2)ψ˜+(1′))+> describe the dynamics and elementary excitations of the non-condensate states and are discussed in conjunction with Landau’s criterion for viscosity. Associated concepts of off-diagonal long-range order and the interpretation of <ψ> as a superfluid order parameter are also introduced. Anderson’s Bose-condensed state, as a phase-coherent wave packet superposition of number states, resolves issues of number conservation. Superconductivity involves bound Cooper pairs of electrons capable of Bose condensation and superfluid behavior. Correspondingly, the two-particle Green’s function has a term involving a product of anomalous bound-Cooper-pair condensate wave functions of the type F(1,2)=−i<(ψ(1)ψ(2))+>≠0, such that G2(1,2;1′,2′)=F(1,2)F+(1′,2′)+G˜2(1,2;1′,2′). Here, G˜2 describes the dynamics/excitations of the non-superfluid-condensate states, while nonvanishing F,F+ represent a phase-coherent wave packet superposition of Cooper-pair number states and off-diagonal long range order. Employing this form of G2 in the G1-equation couples the condensed state with the non-condensate excitations. Taken jointly with the dynamical equation for F(1,2), this leads to the Gorkov equations, encompassing the Bardeen–Cooper–Schrieffer (BCS) energy gap, critical temperature, and Bogoliubov-de Gennes eigenfunction Bogoliubons. Superconductor thermodynamics and critical magnetic field are discussed. For a weak magnetic field, the Gorkov-equations lead to Ginzburg–Landau theory and a nonlinear Schrödinger-like equation for the pair wave function and the associated supercurrent, along with identification of the Cooper pair density. Furthermore, Chapter 13 addresses the apparent lack of gauge invariance of London theory with an elegant variational analysis involving re-gauging the potentials, yielding a manifestly gauge invariant generalization of the London equation. Consistency with the equation of continuity implies the existence of Anderson’s acoustic normal mode, which is supplanted by the plasmon for Coulomb interaction. Type II superconductors and the penetration (and interaction) of quantized magnetic flux lines are also discussed. Finally, Chapter 13 addresses Josephson tunneling between superconductors.

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