Quantum Monte Carlo Study of the electronic properties of delafossite 2H-AgNiO<sub>2</sub> and AgNi<sub>x</sub>Co<sub>1-x</sub>O<sub>2</sub>
ORAL
Abstract
The delafossite AgNiO2 has received a great deal of attention due to its unique semi-metallic nature, which only AgNiO2 exhibits among the d10-based delafossites, and its antiferromagnetism in the NiO2 layers. Due to the semi-metallic nature of AgNiO2, the existence of a metal-insulator transition has been predicted in AgNixCo1-xO2 structures consisting of an admixture of insulating CoO2 into the NiO2. The electronic structure of AgNiO2 have been studied using Density Functional Theory (DFT), but a detailed predictive study that includes accurate electron correlations in NiO2 has been missing. Using Quantum Monte Carlo method, we obtain accurate estimates for the electronic properties of AgNiO2. We also conclude that the rather strong electron correlations in AgNiO2 were underestimated in DFT studies. Finally, we study various compositions of AgNixCo1-xO2 and estimate their formation energies and band gap openings with Co substitutions in order to investigate the electronic properties and phase stability of the mixtures.
*This work was supported by U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division, as part of the Computational Materials Sciences Program and Center for Predictive Simulation of Functional Materials.
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Presenters
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Hyeondeok Shin
- Argonne National Laboratory