Nanoscale investigation on electric field induced ferroelectric phase transitions in the rhombohedral PMN-PT single crystal

The excellent piezoelectric property of Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) single crystals has attracted increasing attentions for their application in electromechanical devices. Generally, the electric field induced phase transition is an important contribution to the piezoelectric response. Understanding the pathway of electric field induced phase transition is essential for the practical application of PMN-PT crystals. Here, evolution of the domain structure and surface screening charges during phase transitions in the (001) oriented 0.72PMN-0.28PT crystal were studied at nanoscale via piezo-response force microscopy (PFM) and Kelvin probe force microscopy (KPFM). In combination with confocal polarized Raman spectroscopy, electric field induced phase transitions were locally studied. PFM tip bias poling in 0.72PMN-0.28PT single crystal results in a rhombohedral to monoclinic phase transition. And the monoclinic phase relaxes back to the rhombohedral at elevated temperatures. Our work provides nanoscale investigations on the electric field induced phase transition, and will be instructive for the practical application of PMN-PT single crystals.(c) 2023 Published by Elsevier B.V.

Automated summary

The domain structure and surface screening charges during phase transitions in the (001) oriented 0.72PMN-0.28PT crystal were investigated at the nanoscale using piezo-response force microscopy (PFM) and Kelvin probe force microscopy (KPFM). Electric field induced phase transitions were studied locally with confocal polarized Raman spectroscopy. It was found that PFM tip bias poling can induce a rhombohedral to monoclinic phase transition in the 0.72PMN-0.28PT single crystal, and the monoclinic phase relaxes back to the rhombohedral phase at elevated temperatures. This study provides valuable insights into the electric field induced phase transition and its practical applications for PMN-PT single crystals.