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arXiv · 2601.14981

Crystal growth and characterization of a hole-doped iron-based superconductor Ba(Fe$_{0.875}$Ti$_{0.125}$)$_2$As$_2$

Yi-Li Sun·Ze-Zhong Li·Yang Li·Hong-Lin Zhou·Amit Pokhriyal·Haranath Ghosh·Shi-Liang Li·Hui-Qian Luo
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Abstract

We report the crystal growth of a new hole-doped iron-based superconductor Ba(Fe$_{0.875}$Ti$_{0.125}$)$_2$As$_2$ by substituting Ti on the Fe site. The crystals are accidentally obtained in trying to grow Ni doped Ba$_2$Ti$_2$Fe$_2$As$_4$O. After annealing at 500 \textcelsius $ $ in vacuum for one week, superconductivity is observed with zero resistance at $T_{c0} \approx 17.5$ K, and about 20\% diamagnetic volume down to 2 K. While both the small anisotropy of superconductivity and the temperature dependence of normal state resistivity are akin to the electron doped 122-type compounds, the Hall coefficient is positive and similar to the case in hole-doped Ba$_{0.9}$K$_{0.1}$Fe$_2$As$_2$. The density functional theory calculations suggest dominated hole pockets contributed by Fe/Ti 3$d$ orbitals. Therefore, the Ba(Fe$_{1-x}$Ti$_{x}$)$_2$As$_2$ system provides a new platform to study the superconductivity with hole doping on the Fe site of iron-based superconductors.

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Yi-Li Sun, Ze-Zhong Li, Yang Li, Hong-Lin Zhou, Amit Pokhriyal, Haranath Ghosh, Shi-Liang Li, Hui-Qian Luo. 2026-01-21. Crystal growth and characterization of a hole-doped iron-based superconductor Ba(Fe$_{0.875}$Ti$_{0.125}$)$_2$As$_2$. https://doi.org/10.1088/1674-1056%2Fae0d5a

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