Superconductivity Observed in Tantalum Polyhydride at High Pressure
Xiujie He, C. L. Zhang, Z. W. Li, S. J. Zhang, Baosen Min, J. Zhang, Kun Lu, Jianfu Zhao, Liehang Shi, Yang Peng, X. C. Wang, S. M. Feng, Jing Song, Luhong Wang, Vitali B. Prakapenka, Stella Chariton, Haozhe Liu, C. Jin
Abstract
We report experimental discovery of tantalum polyhydride superconductor. It was synthesized under high-pressure and high-temperature conditions using diamond anvil cell combined with in situ high-pressure laser heating techniques. The superconductivity was investigated via resistance measurements at pressures. The highest superconducting transition temperature T c was found to be ∼ 30 K at 197 GPa in the sample that was synthesized at the same pressure with ∼ 2000 K heating. The transitions are shifted to low temperature upon applying magnetic fields that support the superconductivity nature. The upper critical field at zero temperature μ 0 H c2 (0) of the superconducting phase is estimated to be ∼ 20 T that corresponds to Ginzburg–Landau coherent length ∼ 40 Å. Our results suggest that the superconductivity may arise from <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>I</mml:mi> <mml:mover accent="true"> <mml:mn>4</mml:mn> <mml:mo>¯</mml:mo> </mml:mover> <mml:mn>3</mml:mn> <mml:mi>d</mml:mi> </mml:mrow> </mml:math> phase of TaH 3 . It is, for the first time to our best knowledge, experimental realization of superconducting hydrides for the VB group of transition metals.