Laboratorio de Magnetismo Aplicado

El Laboratorio de Magnetismo Aplicado esta equipado con las siguientes técnicas de caracterización.

1. Magneto-optical characterization
The laboratory is currently equipped with 3 MOKE set-ups, 2 of them are also ellipsometers [ ], so called Generalized Magneto-Optical ellipsometry. With this technique, we can obtain the full dielectric tensor of a magnetized material. With the combined capabilities of our set-ups we can make L-MOKE, T-MOKE and polar MOKE at light wavelengths from 405 to 950 nm and magnetic fields up to 0.5 T. It is also possible to determine the complex refractive index, Kerr rotation and Kerr ellipticity values with a sensitivity down to few micro-rad. Nano-rad resolution is expected with upcoming upgrades.

2. High frequency characterization
Our broadband FMR set-up from NanOsc has a frequencie range from 2 to 18 GHz and magnetic field up to 0.5 T for IP configuration and 1.3 T for OOP configuration. Physical quantities as the g-factor, saturation magnetization, magnetocrystalline anisotropy fields, and Gilbert’s damping of thin ferromagnetic films (down to ~2 nm) can be determined in a matter of minutes. We also have made methodological contributions [ ] to this experimental technique for the accurate determination, precision less than 1%, of the g-factor and saturation magnetization. We can measure Gilbert’s damping in a range from 5×10-5 up to 1×10-2 for both IP and OOP configurations. As an extra/feature, the system includes a waveguide to detect the recently discovered Inverse Spin Hall Effect (ISHE).
Our Giant Magneto Impedance (GMI) setup is composed by; a data acquisition system (GPIB card + computer), Helmholtz coils that generate a magnetic field up to 120 Oe and a HP875C Network Analyzer that measures the transmission and reflection of electrical signals in electrical networks at microwave frequencies (from 30 kHz to 6 GHz). The waveguide allows measuring different materials geometries such as; ribbons, microwires and thin films.
Combining our MOKE system with microwave source we have also successfully implemented a Microwave assisted magnetization Reversal (MAMR) set up which allows determining the dependence of the magnetization reversal with the microwave frequency for fields upto 0.5 Teslas and frequencies upto 26 GHz.

3. Magnetic characterization
Homemade Alternating Gradient Magnetometer (AGM) with the capability to measure both IP and OOP configurations with a sensitivity of 10-6 e.m.u. and applied magnetic fields up to 1 Tesla. The device is capable of measuring magnetic hysteresis loops and FORC. We have measured Py and CoFeB thin films with a thickness of less than 1 nm. Additionally, we have also developed an inductive magnetometer with exceptional sensitivity able to measure both hysteresis loops and FORC curves at selected frequencies in ribbon, microwires and even thin films. The system is right now under patent process.

4. Thermal Spin transport set-up
Our homemade set-up measures the Spin Seebeck effect, Nernst effect, and Spin Hall magneto resistance for magnetic fields of up to 1000 Oe and temperature difference of up to 100 K. It can also determine the Spin Seebeck dependence on the applied magnetic field direction.

Personal vinculado: Carlos Garcia, Pablo Ibarra, Alejandro Jara, Claudio Gonzalez, Marian Abellan, Cristian Romanque, Luis Lizardi.