Magnetic properties of bismuth-substituted neodymium iron garnet films on Gd₃Ga₅O₁₂(100) substrates determined by ferromagnetic resonance measurements

Abstract

Magnetic properties of Nd 3%x Bi x Fe 5 O 12 (0 : x : 3) films prepared by metal organic decomposition on Gd 3 Ga 5 O 12 (100) substrates have been investigated. The Faraday rotation angle θ F increased with bismuth concentration. The uniaxial anisotropy constant K u , cubic magnetocrystalline anisotropy constant K 1 , gyromagnetic ratio γ, g-factor, and FMR line width ΔH were determined by ferromagnetic resonance measurements. K u was positive and K 1 was negative for all samples. K u decreased from 9.83 ' 10 4 to 2.05 ' 10 4 erg/cm 3 as x increased from 0 to 3. K 1 was almost constant irrespective of x, and it took a value between %3.28 ' 10 4 and %2.08 ' 10 4 erg/cm 3 . γ, g-factor, and ΔH also decreased with increasing bismuth concentration. From the results of the investigation of the in-plane tensile strain applied to the films, the effect of strain on K u is considered to be small.

Spin Seebeck Effect in Neodymium Iron Garnet Multilayers

“…(7,8) For example, Bi-substituted iron insulator garnets are of interest owing to their strong spin-orbit interaction to generate pure spin currents with the flexible control of magnetic properties by changing the composition. (9,10) As mentioned above, the simple experimental geometry of SSE-based sensors further allows two independent paths for heat and electric currents; thus, two different materials can be optimized separately for the implementation of thin films even over large surfaces also. In the present work, a technique that combines metal organic decomposition (MOD) and spin coating, is employed to deposit Nd 2 BiFe 5 O 12 (NIG)-and Nd 2 BiFe 4 Ga 1 O 12 (NIGG)-based multilayer structures as it is not only a low-cost but also an easy scaling process by simply increasing the area of coating.…”