Synthesis of the Elusive <i>S</i> = ¹/₂ Star Structure: A Possible Quantum Spin Liquid Candidate

Abstract

Materials with two-dimensional, geometrically frustrated, spin-¹/₂ lattices provide a fertile playground for the study of intriguing magnetic phenomena such as quantum spin liquid (QSL) behavior, but their preparation has been a challenge. In particular, the long-sought, exotic spin-¹/₂ star structure has not been experimentally realized to date. Here we report the synthesis of [(CH₃)₂(NH₂)]₃[Cu^II₃(μ₃-OH)(μ₃-SO₄)(μ₃-SO₄)₃]·0.24H₂O with an <i>S</i> = ¹/₂ star lattice. On the basis of the magnetic susceptibility and heat capacity measurements, the layered Cu-based compound exhibits antiferromagnetic interactions but no magnetic ordering or spin freezing down to 2 K. The spin-frustrated material appears to be a promising QSL candidate.