Magnetic structure of the quasicrystal Cd6Tb 1/1 approximant crystal

Quasicrystals and their related approximant crystals exhibit unique atomic structures that can give rise to novel magnetic ground states. Among the Tsai-type approximant crystals, the Cd6Tb 1/1 approximant is particularly intriguing as its electron-per-atom ratio of 2.14 and negative Curie-Weiss temperature suggest it may host a new form of non-collinear magnetic order, distinct from the whirling antiferromagnetic structures found in previously studied Au-based approximants.

Despite being the first antiferromagnetic Tsai-type approximant discovered over a decade ago, the magnetic structure of Cd6Tb has remained unexplored, primarily due to the high neutron absorption of cadmium. This proposal aims to unveil the magnetic ground state in Cd6Tb through powder neutron diffraction measurements on the WISH diffractometer at ISIS.

Diffraction patterns will be collected at 2K, 10K, 20K and 30K, spanning the three observed magnetic transitions at 2.4K, 18K and 23K. Rietveld refinement analysis will enable determination of the magnetic structure across the different regimes. Characterizing this putatively new magnetic texture will deepen our fundamental understanding of magnetism in aperiodic systems and the role of chemical composition in realizing diverse spin textures predicted by theory.