Investigation of Antiferromagnetic Chromium and Dysprosium Using the Pump-Probe Type Method on a New Pulsed Magnetic Field Setup

The growing amount of digital data requires the development of high-speed, lowpower and high-density logic and memory electronic devices. Such technological progress requires a detailed understanding of the fundamental properties of the material and ways to manipulate them. One of the magnetic research areas which has great potential in solving the problem of big data storage is spintronics. Now ferromagnetic materials are the most common in spintronics, however, antiferromagnetic materials can overtake them due to the higher speed of spin switching, reduced noise level due to the low interaction between oppositely oriented spins. In the study of antiferromagnetic materials, the pump-probe method is often used with various pumping mechanisms: an optical laser, an electric current, or X-rays. This project is focused on the first studies of antiferromagnetic materials using the pump-probe type method on a new Pulsed Magnet (PUMA) setup at MID instrument at European XFEL. For this research two different antiferromagnetic samples Dysprosium (Dy) and Chromium (Cr) were chosen to demonstrate the first application of the new method. Both samples feature structural change at low temperatures; however, Dy requires low magnetic field and Cr needs a high magnetic field to affect the spin direction. The PUMA setup was successfully commissioned and several experiments were carried out. Using developed data analysis procedures, a temperature dependence for Dy lattice parameter agreed with theoretical expectations and phase diagram was confirmed. The evaluation of the the radiation damage was carried out using charge reflection of Cr sample, since both charge and magnetic reflections require significant X-ray energy for good signal to noise ratio. As a part of the confirmation of the magnetic nature of the found reflections, they were tracked along with the warming up over Neel temperature. Also the parameters of magnetic reflections were studied in the low temperature region of the spin polarization transition. Finally, both charge and magnetic reflections were tracked with application of magnetic field pulse up to 12.5 T above and below spin-flip transition temperature.