ICAMS / Interdisciplinary Centre for Advanced Materials Simulation

Atomistic simulation of structural and phase stability

Thomas Hammerschmidt

The research group has its focus on the reliable and robust prediction of structural stability and phase stability of technologically relevant materials. In order to make direct contact to experiments we include finite temperature, complex microstructures and multi-component chemistry.

Current topics comprise (i) precipitates of intermetallic phases, in particular topologically close-packed phases in steels and superalloys, (ii) extended defects such as planar faults and dislocations in superalloys and high-entropy alloys, (iii) magnetism at finite temperature in iron and steel and (iv) degradation of cathode materials in Li-ion batteries during dis-/charging. These topics are addressed with a hierarchy of atomistic simulation methods that range from high-throughput density-functional theory calculations to tight-binding and analytic bond-order potentials.

The focus of the research group is particularly the development, implementation and application of bond-order potentials for large scale atomistic simulations. The parameterization of the bond-order potentials is carried out with a semi-automatic parametrization scheme based on tight-binding models. The atomistic simulations are complemented by the development and application of structure maps. These maps chart the bonding chemistry of known compounds based on physically intuitive descriptors that enable us to predict structural stability in novel multi-component alloys.

poster-hammerschmidt2

Group Members

 

Competences

  • analytic bond-order potentials
  • structure maps for d-d and p-d valent systems
  • automated high-throughput density-functional theory calculations
  • structural stability, point defects and interfaces of intermetallic phases (e.g. in Ni-based and Co-based superalloys)
  • magnetism at finite temperature in iron and steel

Recent publications

P. Wang, J. Koßmann, U. R. Kattner, M. Palumbo et al. Thermodynamic assessment of the Co-Ta system Calphad, 64, 205-212, (2019)

T. Hammerschmidt, B. Seiser, M. Ford, A. N. C. Ladines et al. BOPfox program for tight-binding and analytic bond-order potential calculations Computer Physics Communications, 235, 221-233, (2019)

C. Teijeiro Barjas, T. Hammerschmidt, R. Drautz, G. Sutmann. Optimized parallel simulations of analytic bond-order potentials on hybrid shared/distributed memory with MPI and OpenMP International Journal of High Performance Computing Applications, 33, 227-241, (2019)

Y. Lysogorskiy, T. Hammerschmidt, J. Janssen, J. Neugebauer et al. Transferability of interatomic potentials for molybdenum and silicon Modelling and Simulation in Materials Science and Engineering, 27, 025007, (2019)

A. G. Kiiamov, Y. Lysogorskiy, F. G. Vagizov, L. R. Tagirov et al. Vibrational properties and magnetic specific heat of the covalent chain antiferromagnet RbFeSe2 Physical Review B, 98, 214411, (2018)

Contact

Dr. Thomas Hammerschmidt
ICAMS
Ruhr-Universität Bochum
44780 Bochum
Germany
Tel: +49 234 32 29375
Fax: +49 234 32 14977

Email: thomas.hammerschmidt@rub.de

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