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arXiv · 0905.0841

Origin of the structural phase transition at 130 K in BaNi$_2$As$_2$: a combined study of optical spectroscopy and band structure calculations

Z. G. Chen·G. Xu·W. Z. Hu·X. D. Zhang·P. Zheng·G. F. Chen·J. L. Luo·Z. Fang·N. L. Wang
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Abstract

BaNi$_2$As$_2$ exhibits a first order structural transition at 130 K. Understanding this structural transition is a crucial step towards understanding the electronic properties of the material. We present a combined optical spectroscopy and band structure calculation study on the compound across the transition. The study reveals that BaNi$_2$As$_2$ is a good metal with a rather high plasma frequency. The phase transition leads to a small reduction of conducting carriers. We identify that this reduction is caused by the removal of several small Fermi surface sheets contributed dominantly from the As-As bonding and Ni-As antibonding states.

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Z. G. Chen, G. Xu, W. Z. Hu, X. D. Zhang, P. Zheng, G. F. Chen, J. L. Luo, Z. Fang, N. L. Wang. 2009-05-08. Origin of the structural phase transition at 130 K in BaNi$_2$As$_2$: a combined study of optical spectroscopy and band structure calculations. https://arxiv.org/abs/0905.0841

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