Parui, Kaushick K.Kulbakov, Anton A.Gumeniuk, RomanCarrillo-Aravena, EduardoFernández-Díaz, María TeresaSavvin, StanislavKorshunov, ArtemGranovsky, SergeyDoert, ThomasInosov, Dmytro S.Peets, Darren C.2025-10-172025-10-172025-10-17https://opara.zih.tu-dresden.de/handle/123456789/1570https://doi.org/10.25532/OPARA-890Article abstract: Disorder in frustrated quantum systems can critically influence their magnetic ground states and drive exotic magnetic behavior. In the S = ½ system ktenasite, Cu₂.₇Zn₂.₃(SO₄)₂(OH)₆·6H₂O, we show that structural disorder drives an unexpected dimensional crossover and stabilizes a rare coexistence of distinct magnetic states. Neutron diffraction reveals significant Cu/Zn mixing at the Cu2 site, which tunes the Cu²⁺ sublattice from a two-dimensional scalene-distorted triangular lattice into a one-dimensional spin-chain network. Magnetic susceptibility, neutron diffraction, ac susceptibility, and specific heat measurements collectively indicate magnetic duality: a coexistence of incommensurate long-range magnetic order below TN = 4 K and a cluster spin-glass state with Tf = 3.28 K at f = 10 Hz. Our findings highlight ktenasite as a rare platform where structural disorder tunes the effective dimensionality and stabilizes coexisting ordered and glassy magnetic phases, offering a unique opportunity to explore the interplay of frustration, disorder, and dimensional crossover in quantum magnets.Attribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/3::32::307::307-013::31::322::322-01