• Venkataramani, Narayanan
• Bhoi, Biswanath
• Prasad, Shiva
• Aiyar, Ramnath P. R. C.
• Kostylev, Mikhail

Abstract

<p>The growth- and frequency-dependent microwave studies on ~ 250 nm thick Y&amp;#x2083;Fe&amp;#x2085;O&amp;#x2081;&amp;#x2082; [yttrium iron garnet (YIG)] films deposited on Gd&amp;#x2083;Ga&amp;#x2085;O&amp;#x2081;&amp;#x2082; (111) (gadolinium gallium garnet) substrates by RF magnetron sputtering has been reported. After the deposition, the thin films were ex-situ annealed in air at 700 &amp;#x00B0;C for different time intervals (2, 4, 6, and 10 h) and a pure YIG phase with preferred (111) orientation was formed. Effective saturation magnetization (4&amp;#x03C0; Meff) has been estimated from ferromagnetic resonance (FMR) data using Kittel's equations. A negative uniaxial magnetic anisotropy has been observed which decreased with the increase in annealing time. The FMR linewidth (&amp;#x0394; H) for the 10 h annealed film was found to be nearly half of the one annealed for 2 h. The 10 h annealed film showed a &amp;#x0394; H value which lies between 30 and 50 Oe over a wide frequency range (2-18 GHz). This improvement in the microwave properties as a result of annealing is attributed to the reduction of defects and relaxation of stress.</p>

Topics

• Deposition
• impedance spectroscopy
• phase
• thin film
• defect
• iron
• Yttrium
• annealing
• magnetization
• Gadolinium
• saturation magnetization
• Gallium