Ba_(2)IrO_(4) is a sister compound of the widely investigated Sr_(2)IrO_(4) and has no IrO_(6) octahedral rotation nor net canted antiferromagnetic moment,thus it acts as a system more similar to the high-T_(c) cuprat...Ba_(2)IrO_(4) is a sister compound of the widely investigated Sr_(2)IrO_(4) and has no IrO_(6) octahedral rotation nor net canted antiferromagnetic moment,thus it acts as a system more similar to the high-T_(c) cuprate.In this work,we synthesize the Ba_(2)IrO_(4) epitaxial films by reactive molecular beam epitaxy and study their crystalline structure and transport properties under biaxial compressive strain.High resolution scanning transmission electron microscopy and x-ray diffraction confirm the high quality of films with partial strain relaxation.Under compressive epitaxial strain,the Ba_(2)IrO_(4) exhibits the strain-driven enhancement of the conductivity,consistent with the band gap narrowing and the stronger hybridization of Ir-t_(2g) and O-2p orbitals predicted in the first-principles calculations.展开更多
By combining the effective Hamiltonian approach and direct ab initio computation, we obtain the phase diagram of SnTiO3with respect to epitaxial strain and temperature. This demonstrates the complex features of the ph...By combining the effective Hamiltonian approach and direct ab initio computation, we obtain the phase diagram of SnTiO3with respect to epitaxial strain and temperature. This demonstrates the complex features of the phase diagram and provides an insight into this system, which is a presumably simple perovskite. Two triple points, as shown in the phase diagram, may be exploited to achieve high-performance piezoelectric effects. Despite the inclusion of the degree of freedom related to oxygen octahedron tilting, the ferroelectric displacements dominate the structural phases over the whole misfit strain range. Finally, we show that SnTiO3can change from hard to soft ferroelectrics with the epitaxial strain.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11774153,11861161004,51772143,11974163,and 51672125)the National Key Research and Development Program of China(Grant No.2016YFA0201104)+1 种基金the Fundamental Research Funds for the Central Universities,China(Grant Nos.0213-14380167 and 0213-14380198)the Hong Kong Research Grants Council(RGC)through the NSFC–RGC Joint Research Scheme,China(Grant No.N PolyU531/18).
文摘Ba_(2)IrO_(4) is a sister compound of the widely investigated Sr_(2)IrO_(4) and has no IrO_(6) octahedral rotation nor net canted antiferromagnetic moment,thus it acts as a system more similar to the high-T_(c) cuprate.In this work,we synthesize the Ba_(2)IrO_(4) epitaxial films by reactive molecular beam epitaxy and study their crystalline structure and transport properties under biaxial compressive strain.High resolution scanning transmission electron microscopy and x-ray diffraction confirm the high quality of films with partial strain relaxation.Under compressive epitaxial strain,the Ba_(2)IrO_(4) exhibits the strain-driven enhancement of the conductivity,consistent with the band gap narrowing and the stronger hybridization of Ir-t_(2g) and O-2p orbitals predicted in the first-principles calculations.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11574246,51390472,U1537210,and 11564010)the National Basic Research Program of China(Grant No.2015CB654903)+1 种基金the Natural Science Foundation of Guangxi Zhuang Autonomous Region(Grant Nos.GA139008 and AA138162)the “111” Project of China(Grant No.B14040)
文摘By combining the effective Hamiltonian approach and direct ab initio computation, we obtain the phase diagram of SnTiO3with respect to epitaxial strain and temperature. This demonstrates the complex features of the phase diagram and provides an insight into this system, which is a presumably simple perovskite. Two triple points, as shown in the phase diagram, may be exploited to achieve high-performance piezoelectric effects. Despite the inclusion of the degree of freedom related to oxygen octahedron tilting, the ferroelectric displacements dominate the structural phases over the whole misfit strain range. Finally, we show that SnTiO3can change from hard to soft ferroelectrics with the epitaxial strain.
