“…Recently, some trials of vector network analyzer ferromagnetic resonance (VNA-FMR) measurement have been reported. [19][20][21][22] In this technique, the sample is mounted on top of a coplanar waveguide (CPW) structure on a wafer. Microwaves are injected via the CPW and the S-parameter is determined from the microwave transmission or reflection loss.…”
We investigated the size effect on ferromagnetic resonance (FMR) in a submicron-wide single permalloy bar. The resonant frequency markedly increased with decreasing bar width to less than 1 m, since the demagnetizing field is effectively modified by changing the bar width even in thin films. The resonant frequency difference between 100-and 1000-nm-wide bars was over 4 GHz in the absence of a magnetic field. This characteristic is promising for practical microwave devices because the desired resonant frequency can be obtained simply by varying the width of narrow ferromagnetic bars so that it is not necessary to change the material or magnetic field.
“…Recently, some trials of vector network analyzer ferromagnetic resonance (VNA-FMR) measurement have been reported. [19][20][21][22] In this technique, the sample is mounted on top of a coplanar waveguide (CPW) structure on a wafer. Microwaves are injected via the CPW and the S-parameter is determined from the microwave transmission or reflection loss.…”
We investigated the size effect on ferromagnetic resonance (FMR) in a submicron-wide single permalloy bar. The resonant frequency markedly increased with decreasing bar width to less than 1 m, since the demagnetizing field is effectively modified by changing the bar width even in thin films. The resonant frequency difference between 100-and 1000-nm-wide bars was over 4 GHz in the absence of a magnetic field. This characteristic is promising for practical microwave devices because the desired resonant frequency can be obtained simply by varying the width of narrow ferromagnetic bars so that it is not necessary to change the material or magnetic field.
“…The magnetic properties of single-crystalline (Kambe, 2005;Brustolon, 2009), polycrystalline (Singh, 2006;Fan, 2010), alloy films (Sihues, 2007), temperature dependence and similar qualities have been studied electromagnetic spectroscopy techniques (Özdemir, 1998;Fermin, 1999;Rameev, 2000;Aktaş, 2001;Budak, 2003;. The magnetic resonance techniques (EPR, FMR) have been applied to the iron oxides, permalloy nanostructure (Kuanr, 2005), clustered, thermocouple connected to the ferromagnet, thin permalloy layer and et al (Guimarães, 1998;Spoddig, 2005;Can, 2012;Rousseau, 2012;Valenzuela, 2012;Bakker, 2012;Maciá, 2012;Dreher, 2012;Kind, 2012;Li, 2012;Estévez, 2012;, 2012(b), 2012(c); Richard, 2012). Magneto-optic (Paz, 2012), dipolar energy contributions (Bose, 2012), nanocrystalline (Maklakov, 2012;Raita, 2012), La0.7Sr0.3MnO3 films (Golosovsky, 2012), La0.67Ba0.33Mn1-yA y O3, A -Fe, Cr , voltage-controlled magnetic anisotropy (VCMA) and spin transfer torque (Zhu, 2012) and the typical properties of the inertial resonance are investigated (Olive, 2012).…”
The following information can be accessed with the help of such resonance experiments. (i) Electrical structure of point defects by looking at the absorption in a thin structure. (ii) The line width with the movement of spin or surroundings isn't changed. (iii) The distribution of the magnetic field in solid by looking at the of the resonance line position (chemical shift and etc.). (iv) Collective spin excitations. Ferromagnetic Resonance-Theory and Applications 2 The atoms of ferromagnetic coupling originate from the spins of d-electrons. The size of μ permanent atomic dipoles create spontaneously magnetized. According to the shape of dipoles materials can be ferromagnetic, antiferromagnetic, diamagnetic, paramagnetic and etc. Ferromagnetic resonance (FMR) technique was initially applied to ferromagnetic materials, all magnetic materials and unpaired electron systems. Basically, it is analogous to the electron paramagnetic resonance (EPR). The EPR technique gives better results at unpaired electron systems. The FMR technique depends on the geometry of the sample at hand. The demagnetization field is observed where the sample geometry is active. The resonance area of the sample depends on the properties of material. The FMR technique is advantageous because it does not cause damage to materials. Also, it allows a three dimensional analysis of samples. The FMR occurs at high field values while EPR occurs at low magnetic field values. Also, line-width of ferromagnetic materials is large according to paramagnetic materials. Exchange interaction energy between unpaired electron spins that contribute to the ferromagnetism causes the line narrowing. So, ferromagnetic resonance lines appear sharper than expected. The FMR studies have been increased since the EPR was discovered in
“…In this example, the initial damping value of 0.02 for the simulations was chosen to shorten the overall calculation time for the transfer matrix. If we consider α = 0.012 47,48 as the initial damping value for the simulations, we found that the eigen damping constant for higher eigenmodes can be reduced to α ≈ 0.006 (Supplementary Material III). Figure 5Eigen damping constants of the eigenmodes.…”
Though varying in nature, all waves share traits in a way that they all follow the superposition principle while also experiencing attenuation as they propagate in space. And thus it is more than common that a comprehensive investigation of one type of wave leads to a discovery that can be extended to all kinds of waves in other fields of research. In the field of magnetism, the wave of interest corresponds to the spin wave (SW). Specifically, there has been a push to use SWs as the next information carriers similar to how electromagnetic waves are used in photonics. At present, the biggest impediment in making SW-based device to be widely adapted is the fact that the SW experiences large attenuation due to the large damping constant. Here, we developed a method to find the SW eigenmodes and show that their respective eigen damping constants can be 40% smaller than the typical material damping constant. From a bigger perspective, this finding means that the attenuation of SW and also other types of waves in general is no more constrained by the material parameters, and it can be controlled by the shape of the waves instead.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
