Exploring the Structural Complexity of Intermetallic Compounds by an Adaptive Genetic Algorithm

Authors

X Zhao, US Department of Energy, Iowa State University
M C. Nguyen, US Department of Energy, Iowa State University
Wenyong Zhang, University of Nebraska-LincolnFollow
C Z. Wang, US Department of Energy, Iowa State University
Matthew J. Kramer, Iowa State UniversityFollow
David J. Sellmyer, University of Nebraska-LincolnFollow
Xingzhong Li, University of Nebraska-LincolnFollow
F Zhang, US Department of Energy
Liqin Ke, Ames Laboratory, US Department of EnergyFollow
Vladimir P. Antropov, Ames Laboratory, US Deparment of EnergyFollow
K M. Ho, US Department of Energy, Iowa State University

Date of this Version

2014

Citation

PRL 112, 045502 (2014)

Comments

U.S. Government work

Abstract

Solving the crystal structures of novel phases with nanoscale dimensions resulting from rapid quenching is difficult due to disorder and competing polymorphic phases. Advances in computer speed and algorithm sophistication have now made it feasible to predict the crystal structure of an unknown phase without any assumptions on the Bravais lattice type, atom basis, or unit cell dimensions, providing a novel approach to aid experiments in exploring complex materials with nanoscale grains. This approach is demonstrated by solving a long-standing puzzle in the complex crystal structures of the orthorhombic, rhombohedral, and hexagonal polymorphs close to the Zr₂Co₁₁ intermetallic compound. From our calculations, we identified the hard magnetic phase and the origin of high coercivity in this compound, thus guiding further development of these materials for use as high performance permanent magnets without rare-earth elements.