Interfacial Charge Induced Magnetoelectric Coupling at BiFeO3/BaTiO3 Bilayer Interface
Interfacial Charge Induced Magnetoelectric Coupling at BiFeO3/BaTiO3 Bilayer Interface
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DOI：
10.1021/am509055f
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发表时间：
2015-04-29
影响因子：
9.5
通讯作者：
Kotnala, R. K.
中科院分区：
文献类型：
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作者：
Gupta, Rekha;Chaudhary, Sujeet;Kotnala, R. K.
采用射频磁控溅射技术制备了不同BiFeO 3厚度的BiFeO 3 BaTiO 3双层薄膜。XRD结果表明薄膜为纯相多晶生长。在室温下观察到铁电极化（2 P（r）类似于30 μ C/cm（2））和磁矩（M-ss类似于33 emu/cc）显着改善。探讨了铁电极化对界面电流传导的影响。在双层界面的电荷的积累和耗尽进行了分析，通过电流-电压测量，进一步证实了从滞后动态电阻和电容-电压曲线。通过室温磁电容分析，进一步研究了双层膜界面晶界感应电荷引起的磁电耦合。发现室温磁电容源于双层界面处的感应电荷，可以通过改变BFO的厚度来控制该感应电荷以获得更高的ME耦合系数。动态磁电耦合进行了研究，并观察到最大纵向磁电耦合为61 mV/cm Oe在50 nm的厚度的BiFeO 3。所观察到的磁电性能是潜在的有用的新型室温磁电和自旋电子器件的应用。
Bilayer thin films of BiFeO3BaTiO3 at different thicknesses of BiFeO3 were prepared by RF-magnetron sputtering technique. A pure phase polycrystalline growth of thin films was confirmed from XRD results. Significantly improved ferroelectric polarization (2P(r) similar to 30 mu C/cm(2)) and magnetic moment (M-ss similar to 33 emu/cc) were observed at room temperature. Effect of ferroelectric polarization on current conduction across the interface has been explored. Accumulation and depletion of charges at the bilayer interface were analyzed by currentvoltage measurements which were further confirmed from hysteretic dynamic resistance and capacitance voltage profiles. Magnetoelectric coupling due to induced charges at grain boundaries of bilayer interface was further investigated by room temperature magnetocapacitance analysis. A room temperature magnetocapacitance was found to originate from induced charge at the bilayer interface which can be manipulated by varying the thickness of BFO to obtain higher ME coupling coefficient. Dynamic magnetoelectric coupling was investigated, and maximum longitudinal magnetoelectric coupling was observed to be 61 mV/cm Oe at 50 nm thickness of BiFeO3. The observed magnetoelectric properties are potentially useful for novel room temperature magnetoelectric and spintronic device applications.