顺磁性La2/3Sr1/3MnO3层对Bi0.8Ba0.2FeO3薄膜多铁性能的影响∗
Influence of paramagnetic La2/3Sr1/3MnO3 layer on the multiferroic property of Bi0.8Ba0.2FeO3 film
摘要
Abstract
Multiferroics simultaneously exhibit several order parameters such as ferroelectricity and antiferromagnetism, rep-resenting an appealing class of multifunctional material. As the only multiferroics above room temperature, BiFeO3 (BFO) becomes an attractive choice for a wide variety of applications in the areas of sensors and spintronic devices. The coexistence of several order parameters brings about novel physical phenomena, for example, the magnetoelectric coupling effect. It allows the reversal of ferroelectric polarization by a magnetic field or the control of magnetic order pa-rameter by an electric field. Heterostructure interface plays an important role in enhancing the ferroelectric and magnetic properties of multiferroic materials. Furthermore, the magnetoelectric coupling at the interface between the antiferro-magnetism BFO and a ferromagnetic film has the close relation with achieving a functional multiferroic-ferromagnetic heterostructure. <br> In order to determine the relationship between the multiferroic property and the interface experimentally, we pre-pare the Bi0.8Ba0.2FeO3(BBFO)/La2/3Sr1/3MnO3(LSMO) heterostructure on an SrTiO3(STO) substrate by pulsed laser deposition, and the structure characteristics and ferroelectric and magnetic properties are investigated. X-ray diffraction analysis shows that BBFO and LSMO films are epitaxially grown as single-phase. The further study by high-resolution transmission electron microscopy determines that the BBFO film has a tetragonal structure. The ferroelectric and magnetic measurements show that the magnetic and the ferroelectric properties are simultaneously improved, and the maximum values of the remnant polarization (2Pr) and the saturation magnetization of the heterostructure at room temperature are about 3.25 µC/cm2 and 112 emu/cm3, respectively. The reasons for enhancing the ferroelectric and ferromagnetic properties of heterostructure are demonstrated by X-ray photoelectron spectrum that shows being unre-lated to the valence states of Fe element. On the contrary, interface effect plays a major role. In addition, the magnetic resistivities and dielectric properties of BBFO/LSMO heterostructure are investigated at temperatures in a range of 50 K to 300 K, finding that magnetoresistance (M R) and magnetodielectric (M D) are respectively about −42.2% and 21.9% at 70 K with a magnetic field of 0.8 T, and the transition of magnetic phase takes place near 180 K. Further-more, the temperature dependences of magnetodielectric and magnetoloss (M L) present opposite tendencies, suggesting that magnetodielectric is caused by Maxwell-Wagner effect and the magnetoresistance. Experimental results reveal that heterogeneous interface effect shows the exceptional advantages in enhancing multiferroic property and magnetoelectric coupling effect of complex heterostructure material. It is an effective way to speed up the application of multiferroic materials.关键词
多铁性/磁电阻/磁介电/界面效应Key words
multiferroics/magnetoresistance/magnetodielectric/interface effects引用本文复制引用
刘恩华,陈钊,温晓莉,陈长乐..顺磁性La2/3Sr1/3MnO3层对Bi0.8Ba0.2FeO3薄膜多铁性能的影响∗[J].物理学报,2016,65(11):117701-1-117701-8,8.基金项目
国家自然科学基金(批准号:61078057,61471301)、陕西省自然科学基金(批准号:2015JM5259,2011GM6013)、西北工业大学基础科研基金(批准号：JC20110270,3102014JCQ01029)、兰州大学磁学与磁性材料教育部重点实验室开放课题(批准号:LZUMMM2013001, LZUMMM2014007)、国家留学基金委(批准号:201303070058)和高等学校博士学科点专项科研基金(批准号20126102110045)资助的课题.@@@@* Project supported by the National Natural Science Foundation of China (Grant Nos.61078057,61471301), Natural Science Foundation of Shannxi Province, China (Grant Nos.2015JM5259,2011GM6013), Foundation for Fundamental Research, Northwestern Polytechnical University, China (Grant Nos. JC20110270,3102014JCQ01029), Open Project of Key Lab-oratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, China (Grant Nos. LZUMMM2013001, LZUMMM2014007), the China Scholarship Council (Grant No.201303070058), and the Ph. D. Pro-grams Foundation of Ministry of Education of China (Grant No.20126102110045) （批准号:61078057,61471301）
