Structural and magnetic properties of the quantum magnet BaCuTe 2 O 6

We investigate the structural and magnetic properties of the quantum magnet BaCuTe2O6. This compound is synthesized in powder and single crystal form for the first time. Synchrotron x-ray and neutron diffraction reveal a cubic crystal structure (P4(1)32) where the magnetic Cu2+ ions form a complex network. Heat capacity and static magnetic susceptibility measurements suggest the presence of antiferromagnetic interactions with a Curie-Weiss temperature of approximate to- 33 K, while long-range magnetic order occurs at the much lower temperature of not approximate to 6.3 K. The magnetic structure, solved using neutron diffraction, reveals antiferromagnetic order along chains parallel to the a, b, and c crystal axes. This is consistent with the magnetic excitations which resemble the multispinon continuum typical of the spin-1/2 Heisenberg antiferromagnetic chain. A consistent intrachain interaction value of approximate to 34 K is achieved from the various techniques. Finally the magnetic structure provides evidence that the chains are coupled together in a noncollinear arrangement by a much weaker antiferromagnetic, frustrated hyperkagome interaction.