Dynamics of phonons in Sr3Ir4Sn13: an experimental study by ultrafast spectroscopy measurements. (26th July 2016)

• Record Type: Journal Article
• Authors: Luo, C W; Cheng, P C; Tu, C M; Kuo, C N; Wang, C M; Lue, C S
• Is Part Of: New journal of physics. Volume 18:Number 7(2016:Jul.)
• Publication Date: 2016-07-26
• Subjects: Sr3Ir4Sn13 -- phonon -- time resolved optical spectroscopy; 64.70.kd -- 78.47.D- -- 78.47.J-; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/18/7/073045
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: We report a study of ultrafast dynamics of photoexcited electrons and phonons in Sr3 Ir4 Sn13 using dual-color transient reflectivity change ( Δ R / R ) measurements. Time resolved optical spectroscopy of collective excitations reveal the marked features near its structural phase transition temperature T * ≃ 147 K. Two distinctive oscillatory timescales in Δ R / R have been clearly resolved. The rapid THz-range oscillations are attributed to the dynamics of the optical phonons which strongly correlate to the structural phase transition. The slow GHz-range oscillatory phenomenon which only occurs below about 150 K is associated with the dynamic response of the longitudinal-acoustic phonons. These low-energy phonons show a softening feature on approaching the transition temperature, also indicating a strong relevance to the structural phase transition. The information that we demonstrated would provide a deeper understanding of the structural phase transition in Sr3 Ir4 Sn13 .