Resonant and non-resonant magnetic x-ray scattering on multiferroic HoFe3(BO3)4

In this presentation I will first give an introduction to PETRA III, a 3rd generation high brilliance synchrotron source. An introduction to concept of resonant diffraction, experimental setup and essentially theoretical background will be presented next. 

Main part of presentation will be focused on magnetic x-ray scattering measurements on multiferroic HoFe3(BO3)4. In this part I will report on the direct measurement of Ho and Fe moments and their magnetic anisotropies through resonant and non-resonant x-ray scattering. In HoFe3(BO3)4 below TN¬ (~38 K), magnetic reflections are found at (h k l) ± (0 0 3/2) positions in the P3121 structure. The temperature dependent investigation of the diffracted intensity of the magnetic (0 0 4.5) reflection as well as full polarization analysis at the Ho L3 edge, allows the direct determination of the Ho ordering behavior and moment direction. The Ho moment direction is found to be along the c axis. Non-resonant x-ray scattering measurements around the spin reorientation transition (TSR ~ 4.5 K) show that the Fe moments flip from an orientation within the ab plane into the c direction.