Crystal Growth, Structure, and Noninteracting Quantum Spins in Cyanochroite, K2Cu(SO4)2·6H2O

Darren C Peets; Maxim Avdeev; Marein C Rahn; Falk Pabst; Sergey Granovsky; Markus Stötzer; Dmytro S Inosov

doi:10.1021/acsomega.1c06143

Crystal Growth, Structure, and Noninteracting Quantum Spins in Cyanochroite, K₂Cu(SO₄)₂·6H₂O

ACS Omega. 2022 Feb 2;7(6):5139-5145. doi: 10.1021/acsomega.1c06143. eCollection 2022 Feb 15.

Authors

Darren C Peets¹, Maxim Avdeev^{2

3}, Marein C Rahn¹, Falk Pabst⁴, Sergey Granovsky^{1

5}, Markus Stötzer⁶, Dmytro S Inosov^{1

7}

Affiliations

¹ Institut für Festkörper- und Materialphysik, Technische Universität Dresden, 01069 Dresden, Germany.
² Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia.
³ School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.
⁴ Anorganische Chemie II, Technische Universität Dresden, 01069 Dresden, Germany.
⁵ Faculty of Physics, M.V. Lomonossow Moscow State University, Moscow 119991, Russia.
⁶ Anorganische Chemie I, Technische Universität Dresden, 01069 Dresden, Germany.
⁷ Würzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter-ct.qmat, Technische Universität Dresden, 01069 Dresden, Germany.

Abstract

The rare mineral cyanochroite, K₂Cu(SO₄)₂·6H₂O, features isolated Cu²⁺ ions in distorted octahedral coordination, linked via a hydrogen-bond network. We have grown single crystals of cyanochroite as large as ∼0.5 cm³ and investigated structural and magnetic aspects of this material. The positions of hydrogen atoms deviate significantly from those reported previously based on X-ray diffraction data, whereas the magnetic response is fully consistent with free Cu²⁺ spins. The structure is not changed by deuteration. Density functional theory calculations support our refined hydrogen positions.