The effects of thickness, polarization, and strain on vibrational modes of 2D Fe 3 GeTe 2

• 全文链接
• 请求原文

作   者：

Weerahennedige, Hiruni;  Irziqat, Mohammed;  Vithanage, Dinushika;  Weerarathne, Hansaka;  Ronau, Zane;  Sumanasekera, Gamini;  Jasinski, Jacek B.; 

作者机构：

University of Louisville Conn Center for Renewable Energy Research; 

关键词：

Strain engineering;  2D materials;  Vibrational modes;  2-DIMENSIONAL MATERIALS;  FERROMAGNETISM;  ARPRS;  Raman spectroscopy;  Fe 3 GeTe 2; 

期刊名称：

Surfaces and interfaces

i s s n：

2468-0230

年卷期：

2024 年 51 卷

页   码：

ARTN 104797-

页   码：

摘   要：

In this study, we investigated the effects of thickness, light polarization, and strain on the Raman spectra of twodimensional (2D) Fe3GeTe2 (FGT) crystals synthesized via chemical vapor transport. The crystals are thoroughly characterized using a combination of microscopic, diffraction, and spectroscopic techniques. Particularly, a systematic angle-resolved polarized Raman spectroscopy study reveals a clear polarization dependence of the Raman intensity in both parallel and crossed polarization directions, with the A1g mode completely disappearing in the crossed polarization direction. The angle-dependent intensity of both the A1g and E22g modes in parallel polarization and the intensity of the E22g mode in the crossed polarization remain constant at all angles. These findings align with predictions from Raman tensor analysis, providing compelling evidence for the unambiguous assignment of the A1g and E22g modes to specific peaks observed in the Raman spectrum of FGT, resolving existing confusion in the literature regarding their assignment. Furthermore, we examined the effect of strain on the Raman spectrum of 2D FGT in-situ using a bending device. Our study, conducted on a monolayer to few-layer 2D FGT deposited onto polyethylene terephthalate and subjected to outward (inward), i.e., tensile (compressive) bending, demonstrates appreciable downshifting (upshifting) of the Raman peak position of both A1g and E22g modes. These findings are particularly significant given that strain engineering represents an effective approach to modulate the magnetic properties of FGT and other 2D magnetic materials.