Structures and Dynamics in Condensed Systems

Personnel

Project Leader(s):
Matthew Kramer

Principal Investigators:
Alan Goldman, Matthew Kramer, Mikhail Mendelev, Ralph Napolitano, Ryan Ott, Xueyu Song, Cai-Zhuang Wang,

Postdoctoral Research Associates:
Shaogang Hao

Overview

This project concentrates on developing quantitative, self-consistent structural descriptions of liquid and amorphous states in metallic systems. Our research moves beyond static structural descriptions towards a detailed thermodynamic understanding of liquid and amorphous states, consistent with structural models. Binary alloys are emphasized to more accurately describe local structure. Moreover, the capabilities of the Materials Preparation Center are utilized to synthesize high-purity alloys having precise composition control. Experimental methods, atomistic simulations, and fundamental theoretical predictions are integrated for the measurement of structure, chemistry, and macroscopic thermodynamic properties in selected liquid and amorphous Al- and Zr-based model systems.

This project utilizes DOE-supported x-ray and neutron sources to capture structural- and chemically-specific details about short- and medium-range order in disordered systems. In addition, targeted scattering data are used to support efforts to develop highly accurate inter-atomic potentials. Simulation approaches include ab initio, constrained reverse Monte Carlo, and classical molecular dynamics using both pair-wise and, more importantly, many-body inter-atomic potentials, including tight-binding and embedded-atom method approaches. A new "embedded-cluster" method for ab initio calculations is pursued to mitigate the artifacts created by periodic boundary conditions of conventional first-principles methods. Combined with experimental data, simulations ultimately allow us to predict—e.g., changes in temperature, strain, or composition—alterations in local and long-range atomic ordering, leading to different disordered structures or perhaps highly-correlated phase transformations.

Highlights

Previous ImageNext Image

Publications

2013
Yue G Q; Wu S; Shen B; Wang S Y; Wang C Z; Ho K M; Kramer M J; Chen L Y . 2013. Effects of strontium impurity on the structure and dynamics of Al88Si12 liquid. Journal of Physics-Condensed Matter. 25:245102. abstract
Export: Tagged BibTex

Liu A C Y; Neish M J; Stokol G; Buckley G A; Smillie L A; de Jonge M D; Ott R T; Kramer M J; Bourgeois L . 2013. Systematic Mapping of Icosahedral Short-Range Order in a Melt-Spun Zr36Cu64 Metallic Glass. Physical Review Letters. 110:205505. abstract
Export: Tagged BibTex

Dahlborg U; Besser M; Kramer M J; Morris J R; Calvo-Dahlborg M . 2013. Atomic dynamics in molten AlCu alloys of different compositions and at different temperatures by cold neutron scattering. Physica B-Condensed Matter. 412:50-60. abstract
Export: Tagged BibTex

Calvo-Dahlborg M; Popel P S; Kramer M J; Besser M; Morris J R; Dahlborg U . 2013. Superheat-dependent microstructure of molten Al-Si alloys of different compositions studied by small angle neutron scattering. Journal of Alloys and Compounds. 550:9-22. abstract
Export: Tagged BibTex

Dahlborg U; Kramer M J; Besser M; Morris J R; Calvo-Dahlborg M . 2013. Structure of molten Al and eutectic Al-Si alloy studied by neutron diffraction. Journal of Non-Crystalline Solids. 361:63-69. abstract
Export: Tagged BibTex

Moorthy S K E; Mendelev M I; Howe J M . 2013. The influence of spatial and temporal averaging on interpretation of HRTEM images of solid-liquid interfaces. Ultramicroscopy. 124:40-45. abstract
Export: Tagged BibTex

2012
Mendelev M I; Kramer M J; Hao S G; Ho K M; Wang C Z . 2012. Development of interatomic potentials appropriate for simulation of liquid and glass properties of NiZr2 alloy. Philosophical Magazine. 92:4454-4469. abstract
Export: Tagged BibTex

Mendelev M I; Kramer M J; Hao S G; Ho K M; Wang C Z . 2012. Computer simulation of the structure of MZr2 liquid and amorphous alloys. Philosophical Magazine. 92:4098-4112. abstract
Export: Tagged BibTex

Wu S; Kramer M J; Fang X W; Wang S Y; Wang C Z; Ho K M; Ding Z J; Chen L Y . 2012. Icosahedral short-range order in amorphous Cu80Si20 by ab initio molecular dynamics simulation study. Intermetallics. 30:122-126. abstract
Export: Tagged BibTex

Warshavsky V B; Song X Y . 2012. Perturbation theory of solid-liquid interfacial free energies of bcc metals. Physical Review E. 86:031602. abstract
Export: Tagged BibTex