Medwal Rohit, Chaudhuri Ushnish, Vas Joseph Vimal, Deka Angshuman, Gupta Surbhi, Duchamp Martial, Asada Hironori, Fukuma Yasuhiro, Mahendiran Ramanathan, Rawat Rajdeep Singh
Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, Singapore 637616, Singapore.
Physics Department, National University of Singapore, Singapore 117551, 2 Science Drive 3, Republic of Singapore.
ACS Appl Mater Interfaces. 2020 Sep 16;12(37):41802-41809. doi: 10.1021/acsami.0c13213. Epub 2020 Sep 2.
The atomically flat interface of the YFeO (YIG) thin film and the GdGaO (GGG) substrate plays a vital role in obtaining the magnetization dynamics of YIG below and above the anisotropy field. Here, magnetoimpedance (MI) is used to investigate the magnetization dynamics in fully epitaxial 45 nm YIG thin films grown on the GGG (001) substrates using a copper strip coil in the MHz-GHz frequency region. The resistance () and reactance (), which are components of impedance (), allow us to probe the absorptive and dispersive components of the dynamic permeability, whereas a conventional spectrometer only measures the field derivative of the power absorbed. The distinct excitation modes arising from the resonance in the uniform and dragged magnetization states of YIG are respectively observed above and below the anisotropy field. The magnetodynamics clearly shows the visible dichotomy between two resonant fields below and above the anisotropy field and its motion as a function of the direction of the applied magnetic field. A low value of a damping factor of ∼4.7 - 6.1 × 10 is estimated for uniform excitation mode with an anisotropy field of 65 ± 2 Oe. Investigation of below and above anisotropy field-dependent magnetodynamics in the low-frequency mode can be useful in designing the YIG-based resonators, oscillators, filters, and magnonic devices.
YFeO（YIG）薄膜与GdGaO（GGG）衬底的原子级平整界面在获取各向异性场上下的YIG磁化动力学方面起着至关重要的作用。在此，磁阻抗（MI）被用于研究在MHz - GHz频率范围内，利用铜带线圈在GGG（001）衬底上生长的全外延45 nm YIG薄膜中的磁化动力学。电阻（）和电抗（）作为阻抗（）的组成部分，使我们能够探测动态磁导率的吸收和色散分量，而传统的光谱仪仅测量吸收功率的场导数。在各向异性场之上和之下分别观察到由YIG均匀磁化态和拖曳磁化态中的共振产生的不同激发模式。磁动力学清楚地显示了在各向异性场上下两个共振场之间明显的二分法及其作为外加磁场方向函数的运动。对于具有65±2 Oe各向异性场的均匀激发模式，估计阻尼因子的低值约为4.7 - 6.1×10 。研究低频模式下与各向异性场相关的磁动力学对于设计基于YIG的谐振器、振荡器、滤波器和磁子器件可能是有用的。
