»ã±¨±êÌâ (Title)£ºA colossal first-order charge density wave transition in 3D R2Ir3Si5 (R = Lu, Er, Ho) and its interplay with magnetism£¨ÔÚÈýάR2Ir3Si5 (R = Lu, Er, Ho) ϵͳÖдæÔÚµÄÅÓµçºÉÃܶȲ¨Ò»¼¶Ïà±äÒÔ¼°ËüºÍ´ÅÐÔµÄÏ໥×÷Óã©

»ã±¨ÈË (Speaker)£ºSitaram Ramakrishnan, Assistant Professor£¨Hiroshima University£©

»ã±¨¹¦·ò (Time)£º2022Äê12ÔÂ20ÈÕ (Öܶþ) 15:00-17:00

»ã±¨µØÖ· (Place)£ºÌÚѶ»áÒé704-121-735£¨ÃÜÂë1220£©

Ô¼ÇëÈË (Inviter)£º±«½ð¿Æ

Ö÷°ì²¿ÃÅ (Organizer)£ºÀíѧԺÎïÀíϵ

»ã±¨ÌáÒª (Abstract)£º

R2Ir3Si5 (R = Lu, Er, Ho) at ambient conditions crystallizes in the orthorhombic Ibam, U2Co3Si5 structure type [1]. Previously, physical property measurements were performed for single-crystal Lu2Ir3Si5 where both charge density wave (CDW) and superconductivity (SC) was found at 200 K and 2 K [2]. However, the symmetry of the crystal in the CDW phase was left unexplored. We have studied both Lu2Ir3Si5 and Er2Ir3Si5 via single crystal x-ray diffraction (SXRD) down to 20 K where we found the structure is actually triclinic I-1 despite the strong monoclinic distortion of the lattice accompanied satellite reflections at q = ¦Ä(1 2 1), ¦Ä = 0.23 ¡« 0.25 and that the Ir-Ir band is responsible for the CDW [3, 4]. For Er2Ir3Si5 we also found from magnetic susceptibility that the CDW is strongly coupled with the magnetism [4].

Currently, upon investigation of another isostructural compound Ho2Ir3Si5 we find that it follows a similar pattern. All three compounds undergo a first-order CDW transition at 200 K for Lu, 150 K for Er and 110 K for Ho. Although, the CDW does not reside on the R atoms, the TCDW is influenced by it. Here I will present the atomic mechanisms of the CDW and its behavior with magnetism in the R2Ir3Si5 family elucidating the similarities and subtle differences between them.

[1] Y. Singh et al., Phys. Rev. B 71, 045109 (2005).

[2] N. Sangeetha et al., Phys. Rev. B 91, 205131 (2015).

[3] S. Ramakrishnan et al., Phys. Rev. B 104, 054116 (2021).

[4] S. Ramakrishnan et al., Phys. Rev. B 101, 060101(R) (2020).