1. Structural Evolution from Hyper-Honeycomb to Honeycomb Networks and Superconductivity in LaPt$_x$Si$_{2-x}$
- Author
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Ramakrishnan, Sitaram, Yamakawa, Tatsuya, Oishi, Ryohei, Yamane, Soichiro, Ikeda, Atsutoshi, Kado, Masaki, Shimura, Yasuyuki, Takabatake, Toshiro, Onimaru, Takahiro, Shibata, Yasuhiro, Thamizhavel, Arumugam, Ramakrishnan, Srinivasan, Yonezawa, Shingo, and Nohara, Minoru
- Subjects
Condensed Matter - Superconductivity ,Condensed Matter - Strongly Correlated Electrons - Abstract
We report the crystal structures and superconductivity (SC) of LaPt$_{x}$Si$_{2-x}$ ($0.5 \leq x \leq 1.0$) that are solid solutions of LaSi$_{2}$ and LaPtSi with centrosymmetric tetragonal ($I4_{1}/amd$, $D_{4h}^{19}$, \#141) and non-centrosymmetric tetragonal ($I4_{1}md$, $C_{4v}^{11}$, \#109) structures, respectively. It was found that at $0.86 \leq x \leq 1.00$, the non-centrosymmetric tetragonal symmetry is preserved, while partial disorder appears in alternating Pt and Si of the hyper-honeycomb network. The superconducting transition temperature $T_{\rm c}$ was drastically reduced from 3.9 K to 1.5 K as $x$ varies from 1.0 to 0.86. Additionally, a hexagonal phase with an AlB$_{2}$-type structure ($P6/mmm$, $D_{6h}^{1}$, \#191) has been discovered at $0.50 \leq x \leq 0.71$ with a honeycomb network of statistically distributed Pt and Si atoms. The hexagonal phase exhibited SC at $T_{\rm c} = 0.38$ K. This system provides an opportunity to investigate the relationship between topological electronic states, SC, and disorders
- Published
- 2024