Low voltage performance of epitaxial BiFeO3 films on Si substrates through lanthanum substitution
Chu, Y.H., Q. Zhan, C.-H. Yang, M.P. Cruz, L.W. Martin, T. Zhao, P. Yu, Ramamoorthy Ramesh, P.T. Joseph, I.N. Lin, W. Tian, D.G. Schlom
We have probed the role of La substitution on the ferroelectric properties of epitaxial BiFe O3 films on SrTi O3 -templated Si. This provides a mechanism to engineer the rhombohedral distortion in the crystal and, thus, control domain structure and switching. With a 10% La substitution, the (Bi0.9 La0.1) Fe O3 film showed well-saturated ferroelectric hysteresis loops with a remanent polarization of 45 μC cm2, a converse piezoelectric coefficient d33 of 45 pmV, and a dielectric constant of 140. Over this range of La substitution, the coercive field systematically decreases such that a coercive voltage of 1 V can been obtained in a 100 nm thick film. These results show promise for the ultimate implementation of this lead-free multiferroic operating at voltages in the range of 2-3 V. © 2008 American Institute of Physics.
Applied Physics Letters
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