Ambient pressure growth of nickelate single crystals with superconductivity up to 96 K under high pressure

by Prof. Junjie Zhang (张俊杰) (Shandong University)

Tuesday 9 Dec 2025, 14:00 → 15:00 Asia/Shanghai

Tsung-Dao Lee Institute/N4F-N400 - meeting room (Tsung-Dao Lee Institute)

Host: Prof. Baiqing Lv 

Venue: TDLI Meeting Room N400

 

Abstract:

Recently, the Ruddlesden-Popper bilayer nickelate La3Ni2O7 has emerged as a superconductor with a transition temperature (Tc) of ~80 K above 14 GPa. Achieving higher Tc in nickelate superconductors, along with the synthesis of reproducible high-quality single crystals without relying on high oxygen-pressure growth conditions, remains a significant challenge. Here we report superconductivity up to 96 K under high pressure in bilayer nickelate single crystals synthesized at ambient pressure. Energy dispersive spectroscopy, single crystal X-ray diffraction, nuclear quadrupole resonance, and scanning transmission electron microscopy evidenced high crystal quality of La2SmNi2O7-δ single crystals. La2SmNi2O7 exhibits clear bulk superconductivity, including zero resistivity (Tc, maxonset = 92 K and Tc, maxzero = 73 K at 21 GPa) and Meissner effect (Tc = 60 K at 20.6 GPa). Our low-temperature high-pressure structural study indicates that both monoclinic and tetragonal structures can support superconductivity in this bilayer nickelate. Furthermore, we established a correlation between Tc under high pressures and in-plane lattice distortion at ambient conditions, corroborated by observing even higher Tc onset of 96 K in La1.57Sm1.43Ni2O7-δ. This study overcomes key limitations in nickelate superconductor crystal growth, resolves the crystal structure in the superconducting state, and demonstrates an effective pathway towards achieving higher Tc. 

[Ref.: Li et al. Nature https://www.nature.com/articles/s41586-025-09954-4 (2025).]

In collaboration with Feiyu Li, Zhenfang Xing, Di Peng,* Jie Dou, Ning Guo, Liang Ma, Yulin Zhang, Lingzhen Wang, Jun Luo, Jie Yang, Jian Zhang, Tieyan Chang, Yu-Sheng Chen, Weizhao Cai, Jinguang Cheng, Yuzhu Wang, Yuxin Liu, Tao Luo, Naohisa Hirao, Takahiro Matsuoka, Hirokazu Kadobayashi, Zhidan Zeng, Qiang Zheng, Rui Zhou, Qiaoshi Zeng,* and Xutang Tao*

 

Biography:

Junjie Zhang is a professor at the State Key Laboratory of Crystal Materials, Shandong University. He received his B. Eng. in 2008 and Ph.D. in 2013 in Materials Science from Shandong University under the supervision of Prof. Xutang Tao. From 2013-2017, he was a postdoc at Argonne National Laboratory’s Materials Science Division, where his research involved systhesis and crystal growth of nickelates and their topotactic reduction. From 2017-2019, he was a postdoc at Oak Ridge National Laboratory’s Materials Science and Technology Division, where his research focused on high-entropy oxides using neutron and x-ray scattering. Appointed to the staff at Shandong University in 2019, his current research emphasizes strategic synthesis, crystal growth, and structural studies of correlated electron transition metal oxides such as nickelates. He is author or co-author of over 60 peer-reviewed papers in internationally recognized journals, including Nature, Nat. Phys., Phys. Rev. Lett., PNAS, J. Am. Chem. Soc. and Adv. Mater.