Interfacial-Strain-Induced Structural and Polarization Evolutions in Epitaxial Multiferroic BiFeO_3(001) Thin Films  

Interfacial-Strain-lnduced Structural and Polarization Evolutions in Epitaxial Multiferroic BiFeO_3(001) Thin Films

作　　者：郭海中[1] Ruiqiang Zhao Kui-juan Jin Lin Gu Dongdong Xiao Zhenzhong Yang Xiaolong Li Le Wang Xu He Junxing Gu Qian Wan Can Wang Huibin Lu Chen Ge Meng He Guozhen Yang 

机构地区：[1]中科院物理所 [2]Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences [3]Collaborative Innovation Center of Quantum Matter [4]Shanghai Synchrotron Radiation Facility(SSRF),Shanghai Institute of Applied Physics,Chinese Academy of Sciences

出　　处：《功能材料信息》2015年第3期19-27,共9页Functional Materials Information

基　　金：supported by the National Basic Research Program of China(Grant Nos.2012CB921403 and 2013CB328706);the National Natural Science Foundation of China(Grant Nos.10904030,11004238,11205235,11134012, 11404380,and 11474349);the Strategic Priority Research Program(B) of the Chinese Academy of Sciences(Grant No. XDB07030200)

摘　　要：Varying the film thickness is a precise route to tune the interfacial strain to manipulate the properties of the multiferroic materials.Here,to explore the effects of the interfacial strain on the properties of the multiferroic BiFeO_3films,we investigated thickness-dependent structural and polarization evolutions of the BiFeO_3 films.The epitaxial growth with an atomic stacking sequence of BiO/TiO_2 at the interface was confirmed by scanning transmission electron microscopy.Combining X-ray diffraction experiments and first-principles calculations,a thickness-dependent structural evolution was observed from a fully strained tetragonality to a partially relaxed one without any structural phase transition or rotated twins.The tetragonality(c/a) of the BiFeO_3 films increases as the film thickness decreases,while the polarization is in contrast with this trend,and the size effect including the depolarization field plays a crucial role in this contradiction in thinner films.These findings offer an alternative strategy to manipulate structural and polarization properties by tuning the interfacial strain in epitaxial multiferroic thin films.Varying the film thickness is a precise route to tune the interracial strain to manipulate the properties of the multiferroic materials. Here, to explore the effects of the interracial strain on the properties of the multiferroic BiFeO3 films, we investigated thickness-dependent structural and polarization evolutions of the BiFeO3 films. The epitaxial growth with an atomic stacking sequence of BiO/ TiO2 at the interface was confirmed by scanning transmission electron microscopy. Combining X-ray diffraction experiments and first-principles calculations, a thickness-dependent structural evolution was observed from a fially strained tetragonality to a partially relaxed one without any structural phase transition or rotated twins. The tetragonality （c/a） of the BiFeO3 films increases as the film thickness decreases, while the polarization is in contrast with this trend, and the size effect including the depolarization field plays a crucial role in this contradiction in thinner films. These findings offer an alternative strategy to manipulate structural and polarization properties by tuning the interfacial strain in epitaxial multiferroic thin films.

关 键 词：功能材料 材料科学 材料 BFO 

分 类 号：TB38[一般工业技术—材料科学与工程]