Special Talk: Investigation of Magnetization Dynamics in Thin Film Structures using Broadband Ferromagnetic Resonance Technique



Investigation of Magnetization Dynamics in Thin Film Structures using Broadband Ferromagnetic Resonance Technique 

  • Dr. Behrouz Khodadadi  
  • 14 May 2018, 15:00
  • Lecture Hall
 
Abstract:
Understanding the magnetization dynamics and the relaxation mechanisms of thin films, apart from being an academic curiosity, is also very important for spintronic applications and for the development of microwave devices. roadband ferromagnetic resonance (FMR) is an excellent tool to study magnetization dynamics and relaxation in magnetic thin films. The behavior of the damping parameter and perpendicular magnetic anisotropy as a function of  nnealing treatment and annealing temperature will be discussed in Co2FeAl Heusler thin films. The experimental results obtained using broadband FMR are very important, considering that Co2FeAl is a promising candidate or spintronic applications such as Spin Transfer Torque MRAM (STT-MRAM). I will also discuss the behavior of ferromagnetic relaxation in NiFe/Gd heterostructures as a function of temperature and more particularly in the vicinity of the Curie temperature of the Gd layer. A detailed FMR study on nickel ferrite (NiFe2O4) thin films with spinel structure will also be presented, showing the effect of deposition parameters, temperature, morphology, and substrate-thin film lattice mismatch on the ferromagnetic relaxation. Furthermore a systematic approach to determine the coupling strength using broadband FMR data in asymmetric interlayer exchangecoupled structures will be discussed. In particular the temperature dependence of the coupling strength of asymmetric CoFe/Ru/CoFe trilayer is compared with the existing theoretical models. I will also discuss experimental results concerning relaxation in these  structures and their agreement with recent theoretical predictions regarding the mutual spin pumping effect in interlayer-coupled systems.