稀土正交铁氧体RFeO3是一种非共线反铁磁绝缘体，具有超快自旋动力学和自旋重取向等特性，对了解反铁磁体中的基态磁构型和磁进动的微观过程具有重要作用，因而受到国内外广泛关注。本文系统研究了TmFeO3的晶体结构、基本磁性、磁光效应、自旋霍尔磁阻及其在太赫兹频段的超快自旋动力学。我们首先通过劳厄衍射技术表征了现有TmFeO3单晶的晶格结构。随后，利用磁性综合测量系统确定了其净磁矩在84.8 K到90.2 K区间内发生的90度旋转。利用磁光克尔显微镜标定了其在室温下的反铁磁磁畴形貌及磁畴翻转过程。接着，我们在TmFeO3/Pt(4 nm)结构中利用反铁磁自旋霍尔磁阻效应实现了对反铁磁奈尔矢量及净磁矩矢量的电学探测，并分析确定了TmFeO3的磁构型随外磁场的变化。最后，利用电子自旋共振系统，通过高频微波激发TmFeO3中的超快自旋进动，测量了TmFeO3的反铁磁共振信号，提取了磁场沿不同晶向时的共振频率-共振场色散关系，并通过理论模型进行拟合分析，得到了反铁磁中基本相互作用的大小。
综上所述，本文对TmFeO3单晶的结构和磁性进行了表征，并且通过研究其反铁磁共振色散关系，加深了我们对反铁磁中超快自旋动力学的理解，从而为反铁磁体未来可能的相关应用提供理论支持。

Rare-earth orthoferrite RFeO3 is a non-collinear antiferromagnetic insulator with notable features such as ultrafast spin dynamics and spin reorientation transition, which playing a crucial role in understanding the ground-state magnetic configurations and the microscopic processes of magnetic precession in antiferromagnets, thereby attracting widespread attention both domestically and internationally. This paper systematically investigates the crystal structure, fundamental magnetism, magneto-optical effects, antiferromagnetic spin Hall magnetoresistance and ultrafast spin dynamics in the terahertz frequency range of TmFeO3. Initially, the lattice structure of TmFeO3 single crystal were characterized using Laue diffraction technique. Subsequently, the net magnetic moment's 90-degree rotation occurring between 84.8 K to 90.2 K was determined using a Magnetic Property Measurement System (MPMS). The antiferromagnetic domain morphology and domain flipping process at room temperature were calibrated using a Magneto-Optical Kerr Microscope (MOKE). Furthermore, in the TmFeO3/Pt (4 nm) structure, the antiferromagnetic Néel vector and the net magnetic moment vector were electrically detected using the antiferromagnetic spin Hall magnetoresistance effect, and the changes in magnetic configurations of TmFeO3 with an external magnetic field were analyzed and determined. Finally, using an Electron Spin Resonance (ESR) system, the antiferromagnetic resonance signals of TmFeO3 were measured by exciting the ultrafast magnetic precession in TmFeO3 through high-frequency microwaves. The resonance frequency-magnetic field dispersion relations along different crystal directions were extracted and analyzed with a theoretical model, obtaining the magnitudes of fundamental interactions in antiferromagnets.
In summary, this paper characterizes the structure and magnetism of TmFeO3 single crystals and deepens our understanding of ultrafast spin dynamics in antiferromagnets through the study of antiferromagnetic resonance dispersion relations, thus providing theoretical support for potential future applications of antiferromagnets.