Magnetic Domain Dynamics Study in Dysprosium

We have studied magnetic domain fluctuations in a Yttrium-Dysprosium-Yttrium tri-layer with X-ray photon correlation spectroscopy (XPCS) in conjunction with resonant soft x-ray magnetic scattering. Dysprosium possesses a helical antiferromagnetic ordering below its N\'{e}el temperature (T$_{N }$= 180K) and above its Curie temperature (T$_{C }\sim $ 85K). With resonant x-ray scattering, we observed the magnetic satellite peak at (0,0,q$_{m})$ due to the helical magnetic structure. We determined the transition temperature and found a shift in T$_{C}$ from the bulk value and hysteresis behavior around T$_{C}$. The transverse correlation length showed a minimum at both T$_{C}$ and T$_{N}$. With the coherent x-rays, we observed magnetic speckles from both static disorder and magnetic domains. The XPCS studies as a function of temperature showed that the magnetic domains are static up to 2000 seconds time scale when T $<$ 175K. Close to T$_{N}$, there appears to be slow dynamics which might be due to domain wall fluctuation.