Anisotropic magnetization dynamics in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mtext>Fe</mml:mtext> <mml:mn>5</mml:mn> </mml:msub> <mml:mtext>Ge</mml:mtext> <mml:msub> <mml:mtext>Te</mml:mtext> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> at room temperature
Alapan Bera, Nirmalya Jana, Amit Agarwal, Soumik Mukhopadhyay
Abstract
The determination of Lande's $g$ factor and the damping constant is central to extracting crucial information about the spin-spin and spin-orbit interactions in magnetically ordered systems. In insulating compounds based on $3d$ elements, the spin-orbit interaction can be effectively probed by investigating the ground state of the corresponding free $3d$ ion within the crystalline environment. For metallic systems, the problem is nontrivial because of additional band structure effects. Here, we investigate the anisotropic magnetization dynamics in bulk single-crystalline ${\mathrm{Fe}}_{5}{\mathrm{GeTe}}_{2}$, a van der Waals 2D itinerant ferromagnet at room temperature, using broadband ferromagnetic resonance spectroscopy. We demonstrate the absence of intrinsic anisotropy of magnetization damping close to room temperature, suggesting diminished role of spin-orbit interaction. However, there is a sizable anisotropy in the Lande's $g$ factor near room temperature, which is attributed to anisotropic critical spin fluctuations.