Brillouin Light Scattering

Electronic & Chemical & Magnetic Characterization (Optical spectroscopy)

Three Brillouin Light Scattering (BLS) experimental setups are available:

1) Conventional Brillouin light scattering (BLS) setup, which allows BLS measurements from thermally excited spin waves in the frequency range between 1 and 200 GHz and a spatial resolution of 30 um. Possibility to apply static magnetic field up to 2 T parallel to the sample surface and to change the incidence angle of light with respect to the sample normal. This allows to explore a wave vector range from 0 to2.2x10^7 rad/m and to measure the dispersion of spin waves (frequency vs wave-vector). Azimuthal rotation of the sample around its normal is also possible to investigate the presence of in-plane magnetic anisotropy.

2) Micro-focused Brillouin light scattering with a lateral resolution down to about 250 nm intensity of the applied magnetic field up to 1 T (out-of-plane) and 0.25 t in-plane. This technique allows to perform 1D and 2D spatial maps of the spin-wave intensity generated by either dc current or a microwave current (up to 20 GHz).

3) Combined micro-Brillouin and micro-Raman set-up to observe collective dynamics (mechanical characterization) by BLS and high frequency molecular vibrational modes (chemical characterization) by Raman in a variety of samples with u-metric spatial resolution (Lateral spatial resolution 500 nm up to 2 um). Frequency resolution: in Brillouin spectra 100 MHz, in Raman spectra 2 cm^(-1)). Laser source at 532 nm. The temperature range covers from -195°C to 300°C. Plus supporting equipment, such as an Atomic Force Microscope operating both in contact and tapping mode and capable of Magnetic force microscopy measurements, and a magneto-optic kerr effect magnetometry apparatus with photo-elastic modulator operating at 50 kHz and lock-in amplification, for measuring hysteresis loops of magnetic nanostructures in the longitudinal configuration and maximum applied field of 200 mT.

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