Quantum Monte Carlo analysis of a charge ordered insulating antiferromagnet: the Ti4O7 Magnéli phase
| Autor: | Luke Shulenburger, Olle Heinonen, Anouar Benali, Jaron T. Krogel, Xiaoliang Zhong, Paul R. C. Kent |
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| Rok vydání: | 2016 |
| Předmět: |
Condensed Matter - Materials Science
Materials science Condensed matter physics Quantum Monte Carlo Oxide General Physics and Astronomy 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences chemistry.chemical_compound chemistry Ferromagnetism Transition metal Lattice (order) 0103 physical sciences Antiferromagnetism Density functional theory Physical and Theoretical Chemistry Spin moment 010306 general physics 0210 nano-technology |
| Zdroj: | Physical Chemistry Chemical Physics. 18:18323-18335 |
| ISSN: | 1463-9084 1463-9076 |
| DOI: | 10.1039/c6cp02067d |
| Popis: | The Magn\'eli phase Ti$_4$O$_7$ is an important transition metal oxide with a wide range of applications because of its interplay between charge, spin, and lattice degrees of freedom. At low temperatures, it has non-trivial magnetic states very close in energy, driven by electronic exchange and correlation interactions. We have examined three low-lying states, one ferromagnetic and two antiferromagnetic, and calculated their energies as well as Ti spin moment distributions using highly accurate Quantum Monte Carlo methods. We compare our results to those obtained from density functional theory-based methods that include approximate corrections for exchange and correlation. Our results confirm the nature of the states and their ordering in energy, as compared with density-functional theory methods. However, the energy differences and spin distributions differ. A detailed analysis suggests that non-local exchange-correlation functionals, in addition to other approximations such as LDA+U to account for correlations, are needed to simultaneously obtain better estimates for spin moments, distributions, energy differences and energy gaps. Comment: Accepter for publication, Physical Chemistry Chemical Physics 2016 |
| Databáze: | OpenAIRE |
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