Magnetoimpedance effect in ferrimagnetic insulator yttrium iron garnet films capped by copper

Magnetoimpedance of Epitaxial Y3Fe5O12 (001) Thin Film in Low-Frequency Regime

“…Thus, the MI measurements provide a precise and effective way to investigate the magnetic properties such as the anisotropy field, effective magnetization, of the magnetic material by exciting the magnetization dynamics. The method can be widely used for metal, semiconductors, and insulators. − , …”

“…In this regard, FMR measurements are usually performed to study the high-frequency magnetization dynamics that are excited by applying a magnetic field higher than that of the anisotropy field of the magnetic material, exhibiting the single domain behavior . The low-frequency magnetization dynamics excited below the anisotropy field of the material are very sensitive to magnetic interactions and therefore require careful study. , In particular, a clean and atomically defined interface of the Gd 3 Ga 5 O 12 (GGG) and YIG with minimum lattice distortion is also a prerequisite to excite magnetodynamics below the anisotropy field of YIG. , Furthermore, the alternative approach of the magnetoimpedance (MI) measurement technique has recently been used to investigate low-frequency magnetization dynamics and to characterize the different magnetic properties of various thin-film materials. − The MI technique measures the changes in complex impedance ( Z = R + jX ) of magnetic materials exposed to the externally applied magnetic field ( H ) where R ∝ ωμ o μ r ″ is the oscillating resistance, X ∝ ωμ o μ r ′ is the reactance, ω is the frequency of the rf signal, and μ o and μ r define the permeability of free space and relative permeability of the material. The relative permeability μ r = μ r ′ – j μ r ″ induces changes in impedance due to the changes in the absorptive component (μ r ″ ) as well as changes in the dispersive component (μ r ′ ) of the permeability. − The MI strip coil method enables the probing of magnetization dynamics in insulators without the need of any additional metal layer. , Since the strip coil geometry is fixed, it can easily be used to compare different samples irrespective of the geometry of any metal layer strip deposited on top of the sample.…”

Assessing the relaxation mechanisms contributions on magnetoimpedance effect in YIG/W bilayers

“…The magnetization dynamics was explored from FMR and MI effect measurements. For the FMR experiment were used a Bruker EPR system operating at 9.83 GHz (mode TE 011 ) [32]. The external magnetic field was applied in the film plane, with modulation of 0.1 Oe at 100 kHz, varied from 2.0 up to 3.5 kOe.…”

Directional Field-Dependence of Magnetoimpedance Effect on Integrated YIG/Pt-Stripline System

“…It is worth remarking that part of the difficulty in obtaining MI results in YIG samples resides in the high resistivity of the material. Nevertheless, recently, it has been shown that the growth of YIG/NM heterostructures, where NM is a non-ferromagnetic metal such as Ag, Cu, and W [ 30 , 31 ], may act as a way to circumvent this adversity and perform investigations on magnetization dynamics through the MI effect in the low frequency regime. In these previous works, the YIG/NM heterostructures were entirely produced by using the Magnetron Sputtering technique.…”

“…The magnetization dynamics in YIG films have been extensively probed through broadband ferromagnetic resonance in recent years; but the link between FMI materials and MI experiments remained elusive until recently [28][29][30][31]. With this spirit, connecting YIG and MI, Kang and coworkers [28], for instance, have addressed the dynamics in YIG spheres and a single-crystalline YIG film deposited by using liquid phase epitaxy.…”