Presentation Information
[15p-WL2_101-10]Controlled Growth of Atomically Flat Thin Films of Electronic Ferroelectric LuFe2O4 Having Anomalous Single-Atomic-Layer Surface Steps
〇Atsushi Fukuchi1, Hiroki Arisawa1,2,3, Eiji Saitoh1,2,3,4,5, Hiroyuki Kobayashi6, Satoshi Okamoto1,6 (1.UT-Sumitomo Chemical Cooperation Program, 2.Dept. Appl. Phys, Univ. Tokyo, 3.RIKEN CEMS, 4.BAI Univ. Tokyo, 5.AIMR Tohoku Univ., 6.Sumitomo Chemical Collaborative Research Cluster)
Keywords:
electronic ferroelectric,charge ordering,epitaxial growth
Electronic ferroelectric is a potential novel class of ferroelectrics, where the polarization generation is based on a charge ordering transition of the material. Mixed-valence LuFe2O4 has been considered a promising candidate for electronic ferroelectricity from the first observation in 2005. However, previous works have shown that atomically flat epitaxial surfaces, which are required toward electric control of the ferroelectricity, are hard to be obtained in LuFe2O4 because of the difficulty in epitaxial growth. To solve this issue, we grew epitaxial thin films of LuFe2O4 on substrates with various kinds of surface structures and explored the possibility of the atomically flat surface formation. Atomically flat growth of LuFe2O4 with defined (0001) surfaces was successfully demonstrated in the thin films using surface-treated YSZ (111) substrates, and interestingly, the existence of an anomalous type of single-atomic-layer-height (0.3 nm) steps was revealed for the film structures.