Possible Tricritical Behavior and Anomalous Lattice Softening in van der Waals Itinerant Ferromagnet Fe3GeTe2 under High Pressure

• 作者: Jie-Min Xu Shu-Yang Wang Wen-Jun Wang Xu-Liang Chen Yong-Hui Zhou Zhao-Rong Yang Zhe Qu
• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2020,（7）
• 所属期刊栏目: CONDENSED MATTER: STRUCTURE, MECHANICAL AND THERMAL PROPERTIES
• 页码范围: 61-64
• 页数: 4页
• 语种: 英文
• DOI: 10.1088/0256-307X/37/7/076202

摘要

We present a high-pressure study of van der Waals ferromagnetic metal Fe3GeTe2 through electrical transport and Raman scattering measurements in diamond anvil cells at pressures up to 22.4 GPa.Upon compression,the ferromagnetic transition temperature Tc manifested by a kink in resistance curve decreases monotonically and becomes undiscernable around Pc =10 GPa,indicative of suppression of the itinerant ferromagnetism.Meanwhile,by fitting the low temperature resistance to the Fermi liquid behavior of R =Ro + AT2,we found that Ro shows a cusp-like anomaly and the coefficient A diverges around Pc.These transport anomalies imply a tricritical point as commonly observed in itinerant ferromagnets under pressure.Unexpectedly,the Raman-active E2g and A1g modes soften remarkably after an initial weak hardening and the peak widths of both modes broaden evidently on approaching Pc,followed by complete disappearance of both modes above this critical pressure.A possible underlying mechanism for such anomalous lattice softening near Pc is discussed.