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Alloy Electronic Structure and Structural Formation Energies and the CE

Duane D. Johnson
MatSE
University of Illinois at Urbana-Champaign
Phone: (217) 256-0319
Email: duanej ---> uiuc.edu

Nikolai Zarkevich
MatSE
University of Illinois at Urbana-Champaign
Email: zarkevich --->uiuc.edu

Lectures

Computer Lab

Download the test files:

And the tutorial notes:

References

(* key references for lectures. **recent useful review for CE )

  1. *Connolly, J.W.D., and Williams, A.R., “Density-functional theory applied to phase transformations in transition-metal alloys,” Phys. Rev. B 27, 5169 (1983).
  2. Sanchez J M, Ducastelle F and Gratias D., Physica A 128, 334 (1984).
  3. Johnson, D.D., Smirnov, A.V., et al., "Temperature-induced configurational excitations for predicting thermodynamic and mechanical properties of alloys," Phys. Rev. B 62, RC11917-20 (2000).
  4. **Mueller, S., “Bulk and surface ordering phenomena in binary metal alloys,” J. Phys.: Condens. Matter 15, R1429–R1500 (2003). PDF, 3.4 MB Review Typ e Article.
  5. *Nikolai Zarkevich and D.D. Johnson, "Reliable Alloy Thermodynamics from Truncated Cluster Expansions," Phys. Rev. Lett. 92, 255702 (2004). (pdf, 213Kb)
  6. N.A. Zarkevich and D.D. Johnson, "Energy Scaling and Surface Patterning of Halogen-Terminated Si(001) Surfaces", Submitted to Elsevier Science, April 2005 (pdf, 1.6 MB)

Details for Lectures and Computer Labs

Lecture will be introduction to energetics of alloy order/disorder and defect energies, electronic mechanism for mixing and ordering, and structural formation energies -- how you get them and what they tell you. Rudiments of the Cluster Expansion (CE) for representing alloy structural formation energies will be presented. Lecture will utilize (un)published results and concepts to help guide intuition and understanding.

Nikolai Zarkevich, MatSE, UIUC, Email: zarkevich --->uiuc.edu

A developing automated CE toolkit that performs ground-state search and Monte Carlo thermodynamics based on a structural energy databases will be briefly presented for use in day 1 labs.

Lab activities: (taught jointly with Gus Hart)
(i) Learn how to calculate and converge formation enthalpies.
(ii) Use data from (i) to do a simple CE fit
(iii) Make ground state search (direct enumeration) using that fit.
(iv) Show how one refines the fit/input database iteratively

Lectures

Presented by Professor Johnson and his research group member, Dr. Nikolai Zarkevich

Electronic Structure Effects and Energies of Alloy Transformations | PDF (5.3 MB)

Basics of Cluster Expansions and Getting a Optimal Cluster Expansion | (PDF, 3.1MB)

Improving Accuracy of Thermodynamics predicted from Multi-scale methods by Global Data integration | (PDF, 2.11MB), (N. Zarkevich)

Computer Lab

Taught with Drs. Nikolai Zarkevich and Dan Finkenstadt and RA Teck Leong

ABINIT will be used to obtain structural energies for an alloy, including addressing structural optimization and k-point convergence issues, and then utilize these results for a fixed-composition and composition-dependent CE.

Download the test files:

And the tutorial notes: