Magnetic Eiaxaticn and Structural Transfor4Aticn in Metallic Glasses

1985 ◽  
Vol 58 ◽  
Author(s):  
R.C. O'Handley
Keyword(s):  
Metallic Glasses ◽  
Local Structure ◽  
Short Range ◽  
Amorphous Materials ◽  
Glassy State ◽  
Local Scale ◽  
Phase Changes ◽  
Reversible Transformation ◽  
Local Structures ◽  
Cobalt Base

ABSTRACTCurrent understanding of the local atomic structure of amorphous materials is reviewed. Sane results of probing short—range order by selected techniques are cited to illustrate the degree of uniformity that exists on a local scale. Observations of phase separation and phase changes are described with particular emphasis on a temperature driven, reversible transformation of the local structure observed magnetically in several cobalt—base glasses. The manifestations and implications of such transformations within the glassy state are examined. Several examples pointing to quasi—crystalline and to non—crystalline (non—space filling) local structures are given.

Local Structures around Zr, Ni and Cu for the Zr67Cu33 and Zr67Ni33 Metallic Glasses

2007 ◽  
Vol 539-543 ◽  
pp. 1959-1963 ◽  
Author(s):  
M. Matsuura ◽  
Masaki Sakurai ◽  
Wei Zhang ◽  
A. Inoue
Keyword(s):  
Synchrotron Radiation ◽  
Metallic Glasses ◽  
Local Structure ◽  
Liquid State ◽  
Local Structures ◽  
The Stability

XAFS measurements of the Cu, Ni and Zr K-edges for the melt-quenched Zr67Cu33 and Zr67Ni33 metallic glasses were curried out using synchrotron radiation at 20K. Fitting calculations for the EXAFS results reveal that local structure around Ni and Zr in Zr67Ni33 is well represented by those for the crystalline Zr2Ni, while local structure around Zr in Zr67Cu33 is better fitted by an icosahedron rather than crystalline Zr2Cu. Such differences of the local structure attribute to the differences of the stability of super-cooled liquid state and glass formability between Zr67Cu33 and Zr67Ni33 metallic glasses.

scholarly journals Controlling the structure and magnetic properties of cluster-assembled metallic glasses

2019 ◽  
Vol 6 (4) ◽  
pp. 727-732 ◽  
Author(s):  
Cahit Benel ◽  
Arne Fischer ◽  
Anna Zimina ◽  
Ralph Steininger ◽  
Robert Kruk ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Impact Energy ◽  
Metallic Glasses ◽  
Local Structure ◽  
Amorphous Materials ◽  
The Impact

The local structure and magnetic properties of amorphous materials are controlled by the impact energy of amorphous clusters.

Effect of Si and P on the Formation and Crystallization of Ti25Hf50Ni25 Metallic Glasses

2002 ◽  
Vol 754 ◽  
Author(s):  
V. T. Huett ◽  
K. F. Kelton
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Metallic Glasses ◽  
Local Structure ◽  
Short Range ◽  
Short Range Order ◽  
Primary Crystallization ◽  
Nucleation And Growth ◽  
Rapid Quenching ◽  
High Degree

ABSTRACTTi255Hf50Ni25 metallic glasses, prepared by rapid quenching, are strongly metastable with a 65°C separation between the glass transition temperature, Tg = 335°C, and the onset temperature for primary crystallization. The deep metastability of the glass is likely due to sluggish nucleation and growth kinetics, limited by the Hf diffusion. The glass crystallizes to a nano-scale microstructure consisting of an icosahedrally symmetric ordered phase. This phase is metastable and transforms to a stable Ti2Ni-type phase with annealing at higher temperatures. The primary crystallization to a metastable icosahedrally-ordered phase suggests that the local structure of the glass contains a high degree of icosahedral short-range order. Here, glass formation and crystallization were studied in alloys containing 2 at.% of Si and P.

DETERMINATION OF THE LOCAL STRUCTURE OF METALLIC GLASSES BY EXAFS

1982 ◽  
Vol 43 (C9) ◽  
pp. C9-43-C9-46 ◽  
Author(s):  
A. Sadoc ◽  
A. M. Flank ◽  
D. Raoux ◽  
P. Lagarde
Keyword(s):  
Metallic Glasses ◽  
Local Structure

Does Local Structure Bias How a Crystal Nucleus Evolves?

2018 ◽  
Author(s):  
Kyle Hall ◽  
Zhengcai Zhang ◽  
Christian Burnham ◽  
Guang-Jun Guo ◽  
Sheelagh Carpendale ◽  
...  
Keyword(s):  
Local Structure ◽  
Molecular Level ◽  
Hydrate Formation ◽  
Mixed Gas ◽  
Local Structures ◽  
Surrounding Environment ◽  
Gas Hydrate Formation ◽  
Significant Research ◽  
Crystal Phases ◽  
Recent Experimental Work

<p>The broad scientific and technological importance of crystallization has led to significant research probing and rationalizing crystallization processes, particularly how nascent</p> <p>crystal phases appear. Previous work has generally neglected the possibility of the molecular-level dynamics of individual nuclei coupling to local structures (e.g., that of the nucleus and its</p> <p>surrounding environment). However, recent experimental work has conjectured that this can occur. Therefore, to address a deficiency in scientific understanding of crystallization, we have</p> <p>probed the nucleation of prototypical single and multi-component crystals (specifically, ice and mixed gas hydrates). Here, we establish that local structures can bias the evolution of nascent</p> <p>crystal phases on a nanosecond timescale by, for example, promoting the appearance or disappearance of specific crystal motifs, and thus reveal a new facet of crystallization behaviour.</p> <p>Analysis of the crystallization literature confirms that structural biases are likely present during crystallization processes beyond ice and gas hydrate formation. Moreover, we demonstrate that</p> <p>structurally-biased dynamics are a lens for understanding existing computational and experimental results while pointing to future opportunities.</p>

Does Local Structure Bias How a Crystal Nucleus Evolves?

2018 ◽  
Author(s):  
Kyle Hall ◽  
Zhengcai Zhang ◽  
Christian Burnham ◽  
Guang-Jun Guo ◽  
Sheelagh Carpendale ◽  
...  
Keyword(s):  
Local Structure ◽  
Molecular Level ◽  
Hydrate Formation ◽  
Mixed Gas ◽  
Local Structures ◽  
Surrounding Environment ◽  
Gas Hydrate Formation ◽  
Significant Research ◽  
Crystal Phases ◽  
Recent Experimental Work

<p>The broad scientific and technological importance of crystallization has led to significant research probing and rationalizing crystallization processes, particularly how nascent</p> <p>crystal phases appear. Previous work has generally neglected the possibility of the molecular-level dynamics of individual nuclei coupling to local structures (e.g., that of the nucleus and its</p> <p>surrounding environment). However, recent experimental work has conjectured that this can occur. Therefore, to address a deficiency in scientific understanding of crystallization, we have</p> <p>probed the nucleation of prototypical single and multi-component crystals (specifically, ice and mixed gas hydrates). Here, we establish that local structures can bias the evolution of nascent</p> <p>crystal phases on a nanosecond timescale by, for example, promoting the appearance or disappearance of specific crystal motifs, and thus reveal a new facet of crystallization behaviour.</p> <p>Analysis of the crystallization literature confirms that structural biases are likely present during crystallization processes beyond ice and gas hydrate formation. Moreover, we demonstrate that</p> <p>structurally-biased dynamics are a lens for understanding existing computational and experimental results while pointing to future opportunities.</p>

scholarly journals Crystalline shielding mitigates structural rearrangement and localizes memory in jammed systems under oscillatory shear

2021 ◽  
Vol 7 (20) ◽  
pp. eabe3392
Author(s):  
Erin G. Teich ◽  
K. Lawrence Galloway ◽  
Paulo E. Arratia ◽  
Danielle S. Bassett
Keyword(s):  
Local Structure ◽  
Disordered Systems ◽  
Amorphous Materials ◽  
Structural Rearrangement ◽  
Oscillatory Shear ◽  
Disordered Materials ◽  
Rheological Measurements ◽  
Particle Level ◽  
Individual Particles

The nature of yield in amorphous materials under stress has yet to be fully elucidated. In particular, understanding how microscopic rearrangement gives rise to macroscopic structural and rheological signatures in disordered systems is vital for the prediction and characterization of yield and the study of how memory is stored in disordered materials. Here, we investigate the evolution of local structural homogeneity on an individual particle level in amorphous jammed two-dimensional (athermal) systems under oscillatory shear and relate this evolution to rearrangement, memory, and macroscale rheological measurements. We define the structural metric crystalline shielding, and show that it is predictive of rearrangement propensity and structural volatility of individual particles under shear. We use this metric to identify localized regions of the system in which the material’s memory of its preparation is preserved. Our results contribute to a growing understanding of how local structure relates to dynamic response and memory in disordered systems.

Simulation of Stress Distribution and Mechanical Response of Metallic Glasses

1998 ◽  
Vol 554 ◽  
Author(s):  
Y. Kogure ◽  
M. Doyama
Keyword(s):  
Stress Distribution ◽  
Metallic Glasses ◽  
Mechanical Response ◽  
Local Density ◽  
Glassy State ◽  
Dynamics Simulation ◽  
Single Atom ◽  
Atomic Interaction ◽  
Embedded Atom ◽  
Embedded Atom Method Potential

AbstractMolecular dynamics simulation of the metallic glasses has been done. The embedded atom method potential function for copper is used to express the atomic interaction. The stress distribution in the glassy state is evaluated from specific volume occupied by single atom and local density in divided cells. The displacements of individual atom under the shear stress are calculated and the correlation between the displacements and the atomic volumes are investigated.

Local Structure of the Amorphous Ni25Zr75-Alloy by Using the Isotope-Substitution Neutron Diffraction Method

1991 ◽  
Vol 46 (11) ◽  
pp. 951-954
Author(s):  
W.-M. Kuschke ◽  
P. Lamparter ◽  
S. Steeb
Keyword(s):  
Neutron Diffraction ◽  
Local Structure ◽  
Short Range ◽  
Short Range Order ◽  
Diffraction Method ◽  
Isotopic Substitution ◽  
Isotope Substitution ◽  
Coordination Numbers ◽  
Structure Factors ◽  
Neutron Diffraction Method

AbstractUsing neutron diffraction as well as the method of isotopic substitution the partial Bhatia-Thornton as well as the partial Faber-Ziman structure factors of amorphous Ni25Zr75 were determined. A compound forming tendency was found. The atomic distances, partial coordination numbers, and the chemical short range order parameter are evaluated.

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