Deciphering chemical order/disorder and material properties at the single-atom level.
Perfect crystals are rare in nature. Real materials often contain crystal defects and chemical order/disorder such as grain boundaries, dislocations, interfaces, surface reconstructions and point defects. Such disruption in periodicity strongly affects material properties and functionality. Despite rapid development of quantitative material characterization methods, correlating three-dimensional (3D) atomic arrangements of chemical order/disorder and crystal defects with material properties remains a challenge. On a parallel front, quantum mechanics calculations such as density functional theory (DFT) have progressed from the modelling of ideal bulk systems to modelling 'real' materials with dopants, dislocations, grain boundaries and interfaces; but these calculations rely heavily on average atomic models extracted from crystallography. To improve the predictive power of first-principles calculations, there is a pressing need to use atomic coordinates of real systems beyond average crystallographic measurements. Here we determine the 3D coordinates of 6,569 iron and 16,627 platinum atoms in an iron-platinum nanoparticle, and correlate chemical order/disorder and crystal defects with material properties at the single-atom level. We identify rich structural variety with unprecedented 3D detail including atomic composition, grain boundaries, anti-phase boundaries, anti-site point defects and swap defects. We show that the experimentally measured coordinates and chemical species with 22 picometre precision can be used as direct input for DFT calculations of material properties such as atomic spin and orbital magnetic moments and local magnetocrystalline anisotropy. This work combines 3D atomic structure determination of crystal defects with DFT calculations, which is expected to advance our understanding of structure-property relationships at the fundamental level.
Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, California 90095, USA.
Yongsoo
Y
Yang
Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, California 90095, USA.|Department of Physics, National Sun Yat-sen University, Kaohsiung 80424, Taiwan.
Chien-Chun
CC
Chen
Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, California 90095, USA.|National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
M C
MC
Scott
National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Colin
C
Ophus
Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, California 90095, USA.
Rui
R
Xu
Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, California 90095, USA.
Alan
A
Pryor
Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, California 90095, USA.
Li
L
Wu
Department of Physics, University at Buffalo, the State University of New York, Buffalo, New York 14260, USA.
Fan
F
Sun
Nanoscale Physics Research Laboratory, School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
Wolfgang
W
Theis
Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, California 90095, USA.
Jihan
J
Zhou
National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Markus
M
Eisenbach
Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.|Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Paul R C
PR
Kent
Department of Physics, University of Nebraska at Omaha, Omaha, Nebraska 68182, USA.
Renat F
RF
Sabirianov
Department of Physics, University at Buffalo, the State University of New York, Buffalo, New York 14260, USA.
Hao
H
Zeng
National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Peter
P
Ercius
Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, California 90095, USA.
Jianwei
J
Miao