Investigation of low temperature magnetic properties of square lattice frustrated magnet Tb₂SrAl₂O₇

Frustrated square-lattice magnets provide fertile ground for emergent quantum phenomena driven by competing exchange interactions. The bilayer perovskite Tb₂SrAl₂O₇, featuring a square arrangement of Tb³⁺ ions and topological Z₈ structural vortices, represents a rare realization of this geometry. In this study, we synthesized high-quality samples and investigated their structural, magnetic, and thermodynamic properties. Tb₂SrAl₂O₇ crystallizes in the tetragonal P4₂/mnm space group, forming a bilayer square lattice where the interplay of strong spin–orbit coupling and competing J₁–J₂ interactions gives rise to pronounced magnetic frustration. Theoretical models predict maximum frustration for J₂/J₁ ≈ 0.5, a regime rarely achieved in real materials. Our experiments reveal a low-temperature magnetic transition near 1.2 K and field-induced features suggestive of competing magnetic phases. In this talk, we will present detailed experimental insights establishing Tb₂SrAl₂O₇ as a model system for exploring magneto-topological coupling and frustration in square-lattice rare-earth magnets.