Spontaneous polarization due to symmetry breaking in the transition metal ditellurides(MTe_(2))family exhibits intriguing sliding ferroelectricity.Although theoretical predictions of MTe_(2)ferroelectric metals with n...Spontaneous polarization due to symmetry breaking in the transition metal ditellurides(MTe_(2))family exhibits intriguing sliding ferroelectricity.Although theoretical predictions of MTe_(2)ferroelectric metals with noncentrosymmetric stacking have been reported,the realization of such polarization structure remains a challenge.Here,we demonstrate the synthesis of PtTe_(2)with non-centrosymmetric stacking layers,in contrast to bulk AA stacking,achieved within a scanning transmission electron microscope(STEM)by irradiating amorphous PtxTeythin flms with an electron beam probe.Cross-sectional STEM imaging combined with frst-principles calculations reveals that the diverse stacking confgurations due to an intralayerπ-stacking system break centrosymmetry in PtTe_(2),giving rise to the out-of-plane polarization.Three-dimensional atomic positions identifed by the atomic electron tomography method further demonstrate the local distortions associated with the non-centrosymmetric stacking layers in PtTe_(2).The understanding of the atomic origin of polarization in PtTe_(2)is of signifcant importance for developing devices that integrate ferroelectricity with metallicity.展开更多
基金supported by the National Key R&D Program of China(Grant Nos.2024YFA1208201,2022YFA1403000,and 2021YFA1400204)the National Natural Science Foundation of China(Grant Nos.52322311,12334001,52427802,12174432,12250710675,and 52461160301)the support from Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices(Grant No.2022B1212010008)。
文摘Spontaneous polarization due to symmetry breaking in the transition metal ditellurides(MTe_(2))family exhibits intriguing sliding ferroelectricity.Although theoretical predictions of MTe_(2)ferroelectric metals with noncentrosymmetric stacking have been reported,the realization of such polarization structure remains a challenge.Here,we demonstrate the synthesis of PtTe_(2)with non-centrosymmetric stacking layers,in contrast to bulk AA stacking,achieved within a scanning transmission electron microscope(STEM)by irradiating amorphous PtxTeythin flms with an electron beam probe.Cross-sectional STEM imaging combined with frst-principles calculations reveals that the diverse stacking confgurations due to an intralayerπ-stacking system break centrosymmetry in PtTe_(2),giving rise to the out-of-plane polarization.Three-dimensional atomic positions identifed by the atomic electron tomography method further demonstrate the local distortions associated with the non-centrosymmetric stacking layers in PtTe_(2).The understanding of the atomic origin of polarization in PtTe_(2)is of signifcant importance for developing devices that integrate ferroelectricity with metallicity.
