Bond competition and phase evolution on the IrTe2 surface

• Published in: Nature communications 2014-11, Vol.5 (1), p.5358-5358, Article 5358
• Main Authors: Li, Qing, Lin, Wenzhi, Yan, Jiaqiang, Chen, Xin, Gianfrancesco, Anthony G., Singh, David J., Mandrus, David, Kalinin, Sergei V., Pan, Minghu
• Format: Article
• Language: English
• Subjects: 639/301/119; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms6358

Compounds with incommensurate structural modulations have been extensively studied in last several decades. However, the relationship between structurally incommensurate/commensurate phases and associated electronic states remains enigmatic. Here we report the coexisting of complex incommensurate structures and highly unusual electronic roughness on the surface of in situ cleaved IrTe 2 by using scanning tunnelling microscopy/spectroscopy, corroborated with extensive density-functional theory calculations. This behaviour is traced to structural instability, which induces a structural transition from a trigonal to a triclinic lattice below transition temperature, giving rise to the formation of unidirectional structural modulations with distinct wavelengths, accompanied by the opening of a ‘pseudo’-gap in the surface layer. With further cooling the surface adopts a structure that reflects an ~6 × periodicity that is different from the bulk 5 × periodicity. Calculations show that the structure distortion is not associated with a charge density wave, but is rather associated with Te p-electron bonding. Understanding the structural relationship and electronic states between incommensurate/commensurate phases remains an ongoing challenge. Here, the authors report incommensurate structures and electronic roughness on the surface of cleaved IrTe 2 .