Mutliferroic vortex and polarization modulated conduction at ferroelectric surfaces Weida Wu, Rutgers University New Bru

1. Mutliferroic vortex and polarization modulated conduction at ferroelectric surfacesWeida Wu, Rutgers University New Brunswick, DMR 0844807 (1) Multiferroics, a magic combination of magnet and ferroelectrics, hold the promise for future low power multifunctional devices, memories and/or sensors. E.g. electric field controlled permanent magnet orientation is one of the promising application of multiferroics At Rutgers, we discovered polarization-modulated local conduction and a striking “cloverleaf” ferroelectric domain pattern on multiferroic hexagonal YMnO3 using ambient cAFM, as shown in Fig. 1(a).[1] The “cloverleaf” domain structure with 6 domains merging at one point is also confirmed by the dark-field transmission electron microscopy (TEM) images shown in Fig. 1(b). The polarization-modulated local conduction mechanism is studied on multiferroic HoMnO3 with state-of-the-art facilities at Argonne National Lab.[2] Results are shown in Fig. 2 and 3. [1] T. Choi et al, Nature Materials, 9, 253 (2010) [2] W. Wu et al, Phys. Rev. Lett., 104, 217601 (2010). (3) (2)

2. Mutliferroic vortex and polarization modulated conduction at ferroelectric surfacesWeida Wu, Rutgers University New Brunswick, DMR 0844807 • Education and Outreach: • Yanan Geng, 2nd year graduate student, working on multiferroics with low temperature magnetic force microscopy (LT-MFM) • Edward Lochochi, Barry Goldwater Scholar (2010), working on multiferroics with piezoresponse force microscopy (PFM) • Tomer Nawrocki, junior, working on electric circuit for LT-MFM • Kelvin Mei, freshman, working on STM tip etching for UHV-LT-STM • Matthew Tsim, high school junior, working on LabView programming for noise analysis • Patrick Chen, freshman, working on data analysis for MFM and STM • Broader Impact • Research on new materials with new properties are vital for the future of civilian well being. Attracting talent students and training of next generation material scientist are crucial for the material science society. Please insert an image or group of images here to illustrate your broader impacts activities. If you need more space, you may reduce the adjacent textbox. Please use lettering that is clearly visible (i.e. not too small). Please include a brief figure caption.