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nanotimes News in Brief

11-05 :: May/June 2011

Dielectrics and Ferroelectricity // Polarization-modulated Conduction and Novel Resistive Memory in Epitaxial BFO Thin Films

B iFeO3

(BFO) thin films as single-phase multifer- roic material show larger electric polarization

and weak ferromagnetism simultaneously at room temperature. BFO is one of the prime candidates for switching magnetism with an electric field, providing an extra degree of freedom in the design of novel functional sensors and multi-state memory devices.

Recently, Dr. WANG Can and his colleagues in Prof. JIN Kuijuan’s group, in Institute of Physics, Chinese Academy of Sciences, have grown epitaxial BFO thin films successfully by using laser molecular beam epitaxy. Polarization-modulated conduction behaviors, including switchable diode effect and ferroelectric resistive switching, have been observed in the BFO thin films. These novel properties are attributed to the polarization-induced variations of Shottky barriers.

In addition, by cooperation with Fudan University, a novel ferroelectric-resistive nonvolatile random access memory consisting of the BFO epitaxial thin films has been investigated. This device has a memo- ry that lasts for months, a sufficiently high on current and on/off ratio to permit ordinary sense amplifiers to measure “1” or “0”, and is fully compatible with complementary metal-oxide semiconductor proces- sing.

Current-voltage curves and ferroelectric hysteresis loops. (a) IV curves of the BFO epitaxial thin films. The hysteresis of IV indicates a resistive switching behavior. (b) IV curves measured with various sweeping voltage. (c) ferroelectric polarization loops of the BFO thin films.

© Beijing National Laboratory for Condensed Matter Phy- sics, Institute of Physics, Chinese Academy of Sciences, China

Can Wang, Kui-juan Jin, Zhong-tang Xu, Le Wang, Chen Ge, Hui-bin Lu, Hai-zhong Guo, Meng He, and Guo-zhen Yang: Switchable diode effect and ferroelectric resistive switching in epitaxial BiFeO3

thin films, In: Applied Phy-

sics Letters, Vol. 98(2011), Issue 19, May 09, 2011, Article 192901 [3 pages], DOI:10.1063/1.3589814: http://dx.doi.org/10.1063/1.3589814