FMR measurements with our Cryostation
Immediately after the official launch of the CryoFMR option from NanOsc for the Montana Instruments Cryostation, the first paper has been published. The paper describes an experiment where researchers of the Universities of Gothenburg and Stockholm analyzed the magneto-dynamic properties of yttrium iron garnet (YIG) thin films at cryogenic temperatures [1].
Spin waves (magnons) can improve data storage and signal processing. However, established ferromagnetic materials are not suited for the spreading of spin waves. They suffer from a high degree of information loss, which is caused by a process called Gilbert damping.
This damping process is a spin-relaxation process of induced precessing magnetization related to spin orbit. Ideally, the Gilbert damping is very small. YIG can meet this requirement as it is a good electrical insulator, is able to generate a pure spin current on the material interface, and has an intrinsic Gilbert damping that is much smaller than that of typical ferromagnetic materials.
Many researchers have already studied YIG at room temperature, but not at cryogenic temperatures. For the above experiment, a commercial PhaseFMR ferromagnetic resonance system from NanOsc was used in the CryoFMR version. YIG thin films of variable temperatures from 8 to 300 K were analyzed and their magneto-dynamic properties characterized as a function of temperature.
The paper shows that the Gilbert damping increases with rising temperatures for different film thicknesses. At room temperature, Gilbert damping increases with decreasing thickness. However, at 8 K it hardly depends on the film thickness any more.
We will be happy to answer your questions on the NanOsc FMR and the optical cryostats from Montana Instruments.
Source:
[1] M. Haider, M. Ranjbar, M. Balinsky, R.K. Dumas, S. Khartsev, and J. Akerman, J. Appl. Phys. 117, 17D119 (2015)
