Local structures around3dmetal dopants in topological insulatorBi2Se3studied by EXAFS measurements

Autor:	Zhen Liu, Zheng Jiang, Xinyuan Wei, Yuying Huang, Jing Zhang, Tiandou Hu, Hong Pan, Shuo Zhang, Mao Ye, Shan Qiao, Fuhao Ji, Jiajia Wang, Fuchun Xi, Zhongqin Yang, Wen Wen
Rok vydání:	2014
Předmět:	Materials science Extended X-ray absorption fine structure Dopant Crystal structure Condensed Matter Physics Electronic Optical and Magnetic Materials Bond length Metal Crystallography Topological insulator visual_art X-ray crystallography visual_art.visual_art_medium Absorption (chemistry)
Zdroj:	Physical Review B. 90
ISSN:	1550-235X 1098-0121
DOI:	10.1103/physrevb.90.094107
Popis:	Transition-metal-doped Bi2Se3 crystals, X0.05Bi2Se3 (X = Cr, Co, Ni, and Cu), are prepared and studied by powder x-ray diffraction and extended x-ray absorption fine structure (EXAFS) measurements to get the local structures around the dopants. Cr atoms substitute Bi atoms and Co atoms may substitute Bi atoms or form Co3Se4 (C2/m) clusters. Cu is also found taking the Bi substitutional site, which differs from the reported superconductor phase of Cu-doped Bi2Se3, suggesting the dependence of site occupancy of Cu in Bi2Se3 on the process of sample growing. For Ni0.05Bi2Se3, Ni atoms form Ni3Se4 (C2/m) clusters. The nearest neighbors of X (X = Cr, Co, and Cu) are Se atoms, and the X-Se bond lengths are extracted from EXAFS as 2.50 angstrom for Cr-Se, 2.40 angstrom for Co-Se, and 2.38 angstrom for Cu-Se, which show the direct evidences of dramatic structural relaxations around 3d dopants. The bond information of local structures around dopants is valuable for subsequent theoretical studies, and can hardly be obtained from other techniques.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::f526e06969cbaeb96396c5f960240a50 https://doi.org/10.1103/physrevb.90.094107 Zobrazit plný text záznamu