Direct observation of incommensurate charge-density wave in overdoped manganites

• Published in: Materials today physics Vol. 5; pp. 7 - 11
• Main Authors: Wang, Y.M., Ge, B.H., Cui, Y.X., Yu, R.C., Chen, S., Ren, Z.F.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2018
• Subjects: Charge ordering; High-resolution transmission electron microscopy; Image deconvolution; Incommensurate modulated structure; Image deconvolution; Incommensurate modulated structure; Charge ordering; High-resolution transmission electron microscopy
• ISSN: 2542-5293; 2542-5293
• DOI: 10.1016/j.mtphys.2018.05.003

The origin of the charge and orbital ordering is still the subject of debate. In manganites, charge ordering (CO) has been traditionally identified as an ordered arrangement of Mn3+ and Mn4+ ions. Here, by high-resolution transmission electron microscopy (HRTEM) in combination with image deconvolution technique and the high-dimensional space description, the nature of CO related to the structural modulation is revealed as an incommensurate charge-density wave (CDW) in real-space for overdoped manganites La0.8Ca2.2Mn2O7. This result resolves the current controversy and confirms the incommensurate CO is not simply a mixture of commensurate ones with different periodicities. In this sense, we provide the first HRTEM imaging evidence for a CDW picture. [Display omitted] •The nature of charge ordering is revealed as an incommensurate charge-density wave (CDW) in real-space by an approach.•This approach includes the deconvolution processing and the high-dimensional space description.•The incommensurate structure at atomic-scale resolution in high-dimensional space is determined.•A picture of CDW is directly obtained from a single high-resolution transmission electron microscopy image for the first time.