MedeA Interface Builder - Connecting Materials

At-a-Glance

The MedeA®[1] Interface Builder creates interfaces and grain boundaries using two different methods. The user can construct a high-symmetry Coincidence-Site Lattice (CSL) grain boundary by customizing template models. In addition, general interface models can be built from two surfaces, allowing for a certain degree of lattice mismatch between the layers. There is no restriction on the surface cells that you start with, they can be as complex or simple as needed.

Key Benefits

  • Easy access to high-symmetry CSL grain boundaries

  • Automated search for possible coherent interfaces

  • Straightforward model construction for subsequent calculation of, for instance, interface energies, effect of impurities on strength, interface thermal resistance (Kapitza resistance), and more

The MedeA Interface Builder includes two powerful tools to generate interface and grain boundary models to be used in atomistic simulations.

1) High-symmetry grain boundary builder: CSL grain boundaries can easily be built from template models in a database. The database contain models with the following crystal lattices: fcc, bcc, hcp, sc, rocksalt, zincblende, wurtzite, nickeline, and fluorite. Both twist-, and tilt boundaries are available, with \(\Sigma\) values up to \(\Sigma\)13. The user can select atom types (elements), and specify lattice parameter and the size of the atomistic model.

2) Surface matching: Two arbitrary surfaces are matched together forming an interface (of twist-type), and rotated with respect to each other in search of low-strain structures. The search for interfaces is conveniently carried out in a background job handled by the JobServer. All found interfaces satisfying the search criteria are collected in a list with geometrical data for each interface. The MedeA graphical interface allows further intuitive, interactive adjustment of interface structures by specifying parameters such as the spacing between the two surfaces and their relative lateral shift.

The resulting models are fully periodic, and can be used directly with MedeA VASP, MedeA LAMMPS, or MedeA MOPAC. Additionally, the user can further edit the structures in MedeA to introduce impurities, vacancies, and interstitial species as needed.

../_images/Sigma5_GBs.png

\(\Sigma\)5(001)/[001] twist grain boundary in nickel with oxygen impurity as described in [2] and ZnS \(\Sigma\)5(3-10)[001] grain boundary

The study of the behaviour of polycrystalline materials is often reduced to the study of the behaviour of their interfaces

A.P. Sutton and R.W. Ballufi, ‘Interfaces in crystalline materials’ (Clarendon, Oxford, 1995)

Key Features

  • High-symmetry grain boundary builder and Interface building by surface matching tool

  • Customizable CSL grain boundaries up to \(\Sigma\)13

  • Surface matching handling of any pair of surfaces

  • Control over maximum lattice mismatch

  • Adjustment of how the lattice mismatch is distributed between the two surfaces to account for differing stiffnesses

  • Adjustment of the spacing (gap) between the two surfaces

  • Interactive adjustment of lateral offsets for full access to the \(\gamma\)-surface

  • Generation of models ready for use in subsequent VASP, LAMMPS, or MOPAC calculations

Required Modules

  • MedeA Environment

  • MedeA Interface Builder

Find Out More

Learn more how the MedeA Interface Builder can be used to build interfaces in the following video tutorial:

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