Topic: Unconventional van der Waals trilayer NiI2 multiferroic
Speaker: Professor Peng Bo, University of Electronic Science and Technology of China (UESTC)
Date and time: July 22, 10:00–11:30
Venue: Room 103, #5 Building of SPST
Host: Xue Jiamin
Abstract:
The search for two-dimensional (2D) van der Waals (vdW) multiferroics is an exciting yet challenging endeavor. To date, the 2D vdW few-layer multiferroic materials and mutual control of electric and magnetic properties have not yet been known although the isolated ferromagnetic and ferroelectric 2D materials have been recently discovered. Here we report the discovery of out-of-plane ferroelectric polarization and long-range magnetic orders in 2D vdW trilayer NiI2 device, as revealed by magneto-optical-electric joint-measurements of scanning reflective magnetic circular dichroism (RMCD) microscopy and polarization-electric field (P-E) hysteresis loop. The evolutions of magnetic domains with magnetic field, and the evolutions between ferroelectric and antiferroelectric phase have been unambiguously observed. More significantly, we realize a robust mutual control of magnetism and ferroelectricity. The switching dynamics of ferroelectric polarization are manipulated by magnetic field, with increasing switching time as magnetic field increase; the magnetic domains are manipulated by a small voltage ranging from ±1V to ±6V at zero magnetic field. This work opens opportunities for exploring multiferroic physics at the limit of single or few atomic layers, and for creating magnetoelectronic devices.
Biography:
Professor Peng Bo received his BSc (Honors) from Lanzhou University in 2005, and obtained his PhD degree from the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences in 2010. He did his postdoctoral research in Singapore from 2010 to 2015. Currently, his research is focused on the 2D multiferroic materials and the mutual control of magnetism and ferroelectricity. Recent five years, he has published more than 40 papers in journals including Nature and Science Advances.