Possible 2D-charge density wave feature of Sr3Ir4Sn13: Electronic and atomic structures
Manish Kumar Srivastava1*, Hsiao-Tsu Wang2, Cheng-Che Wu1, Shang-Hsien Hsieh1, Yu-Fu Wang1, Chin-Shan Lue3, Jeng-Lung Chen4, Chih-Wen Pao4, Jyh-Fu Lee4, Chao-Hung Du1, Maw-Kuen Wu2, Way-Faung Pong1
1Physics, Tamkang University, Tamsui, Taiwan
2Physics, Nation Tsing Hua University, Hsinchu, Taiwan
3Physics, Nation Cheng Kung University, Tainan, Taiwan
4National Synchrotron Radiation Research Center, Hsinchu, Taiwan
* presenting author:Manish Srivastava, email:manish2007bhu@gmail.com
Modulated electronic and atomic structures in high quality single crystal of possible two-dimensional charge density wave (2D-CDW) material Sr3Ir4Sn13 has been observed by using temperature-dependence x-ray scattering, x-ray near-edge structures (XANES) and extended x-ray fine structure (EXAFS) techniques. The temperature dependent x-ray scattering shows the existence of (2.5, 2.5, 0) modulated satellites peak below the temperature T*(~147K), which might be the indicative of possible 2D-CDW properties in (1 1 0) plane at temperature T < T*. Ir L3-edge XANES demonstrate the increased number of unoccupied Ir 5d states in (1 1 0) plane at T< T*, whereas, no significant change is observed for Sn 6p states in the Sn K-edge XANES, which suggests that the Ir 5d unoccupied states play an important role in the anomalous resistivity transition. Based on EXAFS bit formula, we could easily see two associated bond lengths in the Sn EXAFS second main peak of Sn1(2)-Sn2 and the difference of these two associated bond lengths is increased as small distortion occurs in (1 1 0) plane at temperature T< T*. These findings elucidate the intimate relationship between 2D-CDW properties and lattice distortion in Sr3Ir4Sn13.

Keywords: CDW material, XANES, EXAFS