Journal of Inorganic Materials ›› 2025, Vol. 40 ›› Issue (6): 675-682.DOI: 10.15541/jim20240471

• RESEARCH ARTICLE • Previous Articles     Next Articles

Characterizations by Piezoresponse Force Microscopy on Relaxor Properties of Pb(Mg,Nb)O3-PbTiO3 Ultra-thin Films

DONG Chenyu1(), ZHENG Weijie1, MA Yifan2, ZHENG Chunyan1, WEN Zheng1,2()   

  1. 1. College of Physics, Qingdao University, Qingdao 266071, China
    2. College of Electronics and Information, Qingdao University, Qingdao 266071, China
  • Received:2024-11-09 Revised:2025-01-19 Published:2025-06-20 Online:2025-01-24
  • Contact: WEN Zheng, professor. E-mail: zwen@qdu.edu.cn
  • About author:DONG Chenyu (1999-), female, Master candidate. E-mail: 18244065981@163.com
  • Supported by:
    National Natural Science Foundation of China(52372113);Taishan Scholar Program of Shandong Province(tstp20240511)

Abstract:

Relaxor ferroelectrics exhibit extensive applications in sensing technology, optoelectronics, high-density memory storage, and neuromorphic computing, owing to their superior dielectric and piezoelectric characteristics. However, conventional methods, including the Sawyer-Tower circuit and the positive-up-negative-down (PUND) pulse train, prove inadequate for nanoscale ultra-thin films, since the relaxor characteristics may be hindered by substantial leakage currents. In this study, a piezoresponse force microscopy (PFM)-based method for characterizing nanoscale relaxor properties was proposed. Taking ultra-thin Pb(Mg,Nb)O3-PbTiO3 (PMN-PT) films as examples, this work compares polarization hysteresis behavior under On-field and Off-field modes of the dual AC resonance tracking (DART) PFM measurements between relaxor PMN-PT and ferroelectric Pb(Zr,Ti)O3 (PZT) thin films with varying thicknesses. Relaxor characteristics of nanometer-thick PMN-PT films are characterized by modulating amplitude of AC readout to eliminate potential false signals. Furthermore, PFM characterizations of PMN-PT ultra-thin films under different in-plane compressive strains and thicknesses demonstrate that the relaxor characteristics are suppressed and ferroelectric properties are observed at relatively large compressive strains of 3.19%. Additionally, the critical thickness for ferroelectric-relaxor transition is identified. These results verify availability of the proposed PFM-based method for characterizing nanoscale relaxor properties. Therefore, this study not only provides a novel characterization method for exploration of the relaxor in ultra-thin films, but also establishes a foundation for understanding the relaxor polarization behavior in ferroelectric materials, thereby advancing applications of relaxor ferroelectric materials in low-dimensional electronic devices.

Key words: relaxor ferroelectric, piezoresponse force microscope, PMN-PT, ultra-thin film, polarization property

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