Large-area non-stoichiometric phase transition in transition metal chalcogenide films.

Journal: Nature materials
Published Date: Jan 16, 2026

Abstract

Phase engineering is of vital importance for determining the material functionalities and expanding the material library. However, the controllable and scalable phase transition of transition metal chalcogenides remains extremely challenging. The microscopic observation of the phase evolution pathway is an essential prerequisite for understanding the phase transition mechanism. Here we atomically observe a non-stoichiometric phase evolution process in large-scale superconducting PdTe2 films under heating through in situ scanning transmission electron microscopy. The unprecedented phase transition from PdTe2 to PdTe via atomic reconstruction is evidenced and theoretically verified by our machine learning molecular dynamics simulations. In particular, forming the intermediate state of PdTe2/PdTe heterostructure during the phase transition robustly generates giant-helicity-dependent terahertz emission due to inversion symmetry breaking. Our results not only provide insights into the atomic reconstruction in transition metal chalcogenides but also offer a general strategy for the fabrication of large-area transition metal monochalcogenide films and heterostructures, potentially applicable for various device applications.

Authors

  • Zhongqiang Chen
    Department of Orthopaedics, Life Science Park of Zhong Guancun, Peking University International Hospital, Life Park Road No.1, Changping District, Beijing, 102206, China.
  • Jin-An Shi
    School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China.
  • Jianqi Huang
    Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, China.
  • Yuan Chang
    1 Department of colorectal Surgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
  • Ruijie Xu
    Department of Respiratory and Critical Care Medicine, the Second Affiliated Hospital, and Centre for Infection Immunity and Cancer (IIC) of Zhejiang University-University of Edinburgh Institute (ZJU-UoE Institute), Zhejiang University School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
  • Kankan Xu
    State Key Laboratory of Spintronics, Jiangsu Provincial Key Laboratory of Third Generation Semiconductors and High Energy Efficiency Devices, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China.
  • Xu Zhang
    China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China.
  • Xudong Liu
    Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
  • Da Tian
    Research Institute of Superconductor Electronics, MOE Key Laboratory of Optoelectronic Devices and Systems with Extreme Performances, School of Electronic Science and Engineering, Nanjing University, Nanjing, China.
  • Yong Zhang
    Outpatient Department of Hepatitis, The Sixth Affiliated People's Hospital of Dalian Medical University, Dalian, Liaoning, China.
  • Sajjad Ali
    Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, China.
  • Xingze Dai
    State Key Laboratory of Spintronics, Jiangsu Provincial Key Laboratory of Third Generation Semiconductors and High Energy Efficiency Devices, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China.
  • Gan Liu
    Department of information and computing science, University of Science and Technology Beijing, Beijing, 100083, China.
  • Zheng Dai
    Health Affairs Institute, Health Sciences Center, West Virginia University, Morgantown, WV 26506, USA.
  • Shuai Zhang
    School of Information, Zhejiang University of Finance and Economics, Hangzhou, China.
  • Fucong Fei
    National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, China.
  • Xiaoxiang Xi
    National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, China.
  • Yufeng Hao
    National Laboratory of Solid State Microstructures, Jiangsu Provincial Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing, China.
  • Liang He
    Cancer Biology Research Center (Key Laboratory of the Ministry of Education), Tongji Medical College, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China.
  • Wu Zhou
    School of Medical Information Engineering, Guangzhou University of Chinese Medicine, Guangzhou, China, 510006.
  • Teng Yang
    National Engineering Laboratory for VOCs Pollution Control Material & Technology, University of Chinese Academy of Sciences, Beijing 100049, China.
  • Junfeng Gao
    College of Biosystems Engineering and Food Science, Zhejiang University, 866 Yuhangtang Road, 5 Hangzhou 310058, China.
  • Feng Ding
  • Yongbing Xu
    State Key Laboratory of Spintronics, Jiangsu Provincial Key Laboratory of Third Generation Semiconductors and High Energy Efficiency Devices, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
  • Fengqi Song
    National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics, Nanjing University Nanjing 210093 P. R. China.
  • Biaobing Jin
    Research Institute of Superconductor Electronics, MOE Key Laboratory of Optoelectronic Devices and Systems with Extreme Performances, School of Electronic Science and Engineering, Nanjing University, Nanjing, China.
  • Xinran Wang
    Department of Pathology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, China.
  • Yi Shi
    College of Food Science and Engineering, Nanjing University of Finance and Economics/Collaborative Innovation Center for Modern Grain Circulation and Safety, Nanjing 210023, People's Republic of China.
  • Rong Zhang
    Internal Medicine - Cardiology Division, UT Southwestern, Dallas, TX, USA.
  • Xuefeng Wang
    Department of Advanced Manufacturing and Robotics, College of Engineering, Peking University, Beijing 100871, China.

Keywords

No keywords available for this article.

External Resources

Popular Topics
Recent Journals