Ferroelectric and Electrical Properties Optimization of Mg-doped BiFeO3 Flexible Multiferroic Films

Der-Yuh Lin,Ming-Cheng Kao,Pei-Li Zhang,Hone-Zern Chen

doi:10.3390/sym12071173

Der-Yuh Lin, Ming-Cheng Kao + Show 2 more

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https://doi.org/10.3390/sym12071173

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Abstract

Bi1-xMgxFeO3 (BMFO, x = 0, 0.02, 0.04, 0.06 and 0.08) multiferroic films were directly synthesized on flexible stainless steel (FSS), save the bottom electrode process, by means of sol–gel spin-coating technology. The effects of different bending conditions on ferroelectric, dielectric and leakage-current properties of BMFO films were investigated. The leakage-current densities of BiFeO3 (BFO, x = 0) and BMFO (x = 0.06) films were 5.86 × 10−4 and 3.73 × 10−7 A/cm2, which shows that the BMFO (x = 0.06) has more than three orders of magnitude lower than that of BFO film. The residual polarization (2 Pr) can be enhanced from 120 to 140 μC/cm2. The proper doping of Mg in BiFeO3 film could provide an effective method for reducing the leakage-current values as well as boosting the ferroelectric properties. In this study, the leakage-current mechanism of low electric field and high electric field of BMFO film is analyzed and established. In addition, the flexible BMFO film maintains practical ferroelectric and leakage-current properties at retention time of 106 s under different symmetry bending conditions. These results indicate that the BFMO film will be very practical in opto-electronic and storage device applications.

Highlights

Nowadays, many new technologies in science have created amazing and rapid development in the miniaturization of devices, and electronic products have made humans an important driving force for the quality of life
The positions of these X-ray diffraction (XRD) peaks are quite similar to those of the standard diffraction pattern data of BFO collected in the JCPDS card
No obvious second phase was observed for all the samples, indicating that the Mg-substitution has a benefit for stabilizing the perovskite structure

Summary

Introduction

Many new technologies in science have created amazing and rapid development in the miniaturization of devices, and electronic products have made humans an important driving force for the quality of life. The rise of flexible electronic products, with excellent flexibility, portability and lightness, is currently actively entering the electronics market [1,2,3,4]. The current electronic products on the market are gradually becoming flexible, which has led many researchers to invest in flexible film research [5,6,7]. Ferroelectric materials have more superior characteristics in memory element applications, and have a wide range of applications including sensors, actuators, piezoelectrics, spin electrons and microelectronic devices. There are many kinds of ferroelectric materials can be used for thin films devices, among which Pb(Zr, Ti), O3 (PZT), SrBi2 Ta2 O9 (SBT), BaTiO3 , BFO, etc. Nonartificial materials that have both ferroelectric and ferromagnetic properties are rarer. BFO film usually has a high leakage-current density due to the oxygen vacancy and the state of iron ions (Fe3+ to Fe2+ state)

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