（Superconductivity in zirconium polyhydrides with Tc above 70K ）
C. L. Zhang, X. He, Z. W. Li, S. J. Zhang, S. M. Feng, X. C. Wang, R. C. Yu, and C. Q. Jin
We report the experimental discovery of superconductivity with critical temperature Tc above 70 K in zirconium polyhydrides, the record high so far for transition metal hydrides. The superconducting zirconium polyhydrides are synthesized at the extreme conditions above 200 GPa & 2000 K by using diamond anvil cell combined with in-situ laser heating. Superconductivity was observed in the samples maintained at the same pressure upon quenched from heating. The upper critical field is estimated to be ~36 Tesla from measuring the shift of Tc as function of applied magnetic fields while the superconducting coherent length is calculated to be about 30 ? based on Ginzburg Landau formula.