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 mu...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.展开更多
We investigated the effects of oxygen vacancies on the structural, magnetic, and transport properties of Lal-xSrxMnO3 （x=0.1, 0.2, 0.33, 0.4, and 0.5） grown around a critical point （without/with oxygen vacancies） ...We investigated the effects of oxygen vacancies on the structural, magnetic, and transport properties of Lal-xSrxMnO3 （x=0.1, 0.2, 0.33, 0.4, and 0.5） grown around a critical point （without/with oxygen vacancies） under low oxygen pressure （10 Pa） and high oxygen pressure （40 Pa）. We found that all films exhibit ferromagnetic behavior below the magnetic critical temperature, and that the films grown under low oxygen pressures have degraded magnetic properties with lower Curie temperatures and smaller magnetic moments. These results show that in epitaxial La1-xSrxMnO3 thin films, the magnetic and transport properties are very sensitive to doping concentration and oxygen vacancies. Phase diagrams of the films based on the doping concentration and oxygen vacancies were plotted and discussed.展开更多
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)
文摘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.
基金supported by the National Key Basic Research Program of China(Grant Nos.2014CB921001,and 2013CB328706)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(GrantNo.QYZDJ-SSW-SLH020)+1 种基金the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(GrantNo.XDB07030200)the National Natural Science Foundation of China(Grant Nos.11574365,11474349,11674385,and 11404380)
文摘We investigated the effects of oxygen vacancies on the structural, magnetic, and transport properties of Lal-xSrxMnO3 （x=0.1, 0.2, 0.33, 0.4, and 0.5） grown around a critical point （without/with oxygen vacancies） under low oxygen pressure （10 Pa） and high oxygen pressure （40 Pa）. We found that all films exhibit ferromagnetic behavior below the magnetic critical temperature, and that the films grown under low oxygen pressures have degraded magnetic properties with lower Curie temperatures and smaller magnetic moments. These results show that in epitaxial La1-xSrxMnO3 thin films, the magnetic and transport properties are very sensitive to doping concentration and oxygen vacancies. Phase diagrams of the films based on the doping concentration and oxygen vacancies were plotted and discussed.
