Capturing Dynamics of Incommensurate Antiferromagnetic Domains with Coherent Soft X-ray Scattering

The observation of antiferromagnetic (AFM) domains and the dynamics of their interfaces remains an elusive problem. The physical origin and dynamics of AFM domains are different from ferromagnetic domains and are largely unexplored. In this work, we have studied the frustrated AFM, Lu₂CoMnO₆, with the brilliant, coherent, soft X-ray flux of the 23ID-1 beamline at NSLS-II [1]. Lu₂CoMnO₆ is a double perovskite with frustrated AFM order leading to incommensurate ordering and dynamic time scales ranging from seconds to days [2-4]. We have probed the AFM domain structure and dynamics of this material with X-ray photon correlation spectroscopy (XPCS). The motion of the domains is revealed by the motion of a speckle pattern in the scattered X-ray beam. We observed faster domain fluctuations below onset of hysteresis at (35K) and explained these observations within the Axial Next-Nearest-Neighbor Ising (ANNNI) model.

References
[1] X. M. Chen, et al, Phys. Rev. Lett. 117, 167001 (2016).
[2] S. Yáñez-Vilar et al, Phys. Rev. B 84, 134427 (2011).
[3] S. Chikara et al, Phys. Rev. B 93, 180405(R) (2016).
[4] Vivien S. Zapf, et al, Phys. Rev. B 93, 134431 (2016).