Near theoretical microwave loss in hot isostatic pressed (hipped) polycrystalline yttrium iron garnet

Abstract

Unusual metallic behavior in nanostructured cobalt ferrite at superparamagnetic regime J. Appl. Phys. 112, 063926 (2012) Investigation of structural, dielectric, and magnetic properties of hard and soft mixed ferrite composites J. Appl. Phys. 112, 054323 (2012) Magneto-optical study of holmium iron garnet Ho3Fe5O12 Low Temp. Phys. 38, 863 (2012) Growth and ferromagnetic resonance of yttrium iron garnet thin films on metalsThe ferromagnetic resonance ͑FMR͒ linewidth, the field dependent effective linewidth, and the parallel pump spin wave linewidth were measured for spheres and disks prepared from a block of hot isostatic pressed ͑hipped͒ polycrystalline yttrium iron garnet ͑YIG͒. All linewidths as well as static magnetization data indicate close to 100% density. Vibrating sample magnetometer measurements give an average saturation induction 4M s of 1825 G. The FMR half-power linewidths for the spheres at 9.5 GHz were 13 Oe. Linewidths measured over the 9.5-18 GHz frequency range show a small but distinct drop and agree with Schlömann's theory of anisotropy-dominated two-magnon scattering for polycrystalline ferrites. The effective linewidth versus field data at 10 GHz show a region of strong absorption that corresponds to the width of the spin wave manifold for low wave numbers and a high field value of about 2 Oe. Parallel pumping measurements give minimum spin wave linewidths of 1.2 and 0.6 Oe at 9 and 16.7 GHz, respectively. The 16.7 GHz spin wave linewidths correspond to half-frequency spin waves at 8.35 GHz. The extrapolated linewidths at zero wave number are about 0.5 Oe and match the established intrinsic linewidths expected for YIG single crystals at 8 -9 GHz. The spin wave linewidths increase linearly with wave number and are consistent with a transit time scattering process with scattering lengths that are about ten times greater than the average grain size.

Microwave ferrites, part 1: fundamental properties

“…49 The data matches with that expected from two-magnon processes due to magnetocrystalline anisotrophy in the randomly oriented grains. The linewidth measured at 9.…”

“…The spin-wave linewidth is obtained from a theoretical analysis using the measured spin-wave instability threshold field. 49 The effective linewidth is derived from the complex susceptibility obtained from measurements of the cavity Q factor and resonance frequency measurements as a function of the applied field. 46 Using the phenomenological equation of motion for the magnetization from Gilbert (Equation 39), 39 one can obtain the effective susceptibility as 50 ( where η is the relaxation rate.…”

High precision metrology based microwave effective linewidth measurement technique

“…2 duction ͑4M s ͒ of this material is 1825 G, as measured by standard vibrating sample magnetometry for an in-plane field of 170 Oe. 35 From the classic Osborn paper, 36 the approximate in-plane and perpendicular-to-plane demagnetizing factors for disk samples can be evaluated from…”

Characterization of Erbium Substituted Yttrium Iron Garnet Films Prepared by Sol-Gel Method

“…The study of yttrium iron garnet (YIG) thin films is becoming more important because of properties that can be extensively used in optical communication [1], magneto-optical devices, and applied in microwave [2]. YIG is the most representative and well-known compound among the rareearth garnets and various magnetizations can be achieved by substitution process.…”