Посилання:Comparative Raman scattering study of Ba₃MSb₂O₉ (M=Zn, Co and Cu) / A. Glamazda, P. Lemmens, S.-H. Do, K.-Y. Choi // Физика низких температур. — 2017. — Т. 43, № 5. — С. 683-691. — Бібліогр.: 22 назв. — англ.
Підтримка:This work was supported by the Korea Research Foundation
(KRF) grant funded by the Korea government (MEST)
(Grant No. 2009-0093817 and No. 2016-911392), as well as
by German-Israeli Foundation (GIF, 1171-486 189.14/2011),
the NTH-School Contacts in Nanosystems:Interactions, Control
and Quantum Dynamics, the Braunschweig International
Graduate School of Metrology and DFG-RTG 1952/1,
Metrology for Complex Nanosystems. S.H.D. was supported
by Chung-Ang University Research Assistant Fellowship.
Raman spectroscopy is combined with lattice dynamic calculations to investigate the magnetic and structural properties of the 6H-perovskite compounds Ba₃MSb₂O₉ (M = Zn, Co and Cu). Unlike the nonmagnetic Ba₃ZnSb₂O₉ compound, the magnetic counterparts Ba₃MSb₂O₉ (M = Co and Cu) show both lattice anomalies for temperatures below 100 K and develop highly correlated spin states below 50 K. This is ascribed to an instability of conventional magnetic excitations for the equilateral triangular antiferromagnet Ba₃CoSb₂O₉ and a coexistence of spin-orbital liquid and random singlet state for the decorated honeycomb compound Ba₃CuSb₂O₉ containing a nearly identical volume fraction of hexagonal and orthorhombic phases. Our results demonstrate that Ba₃MSb₂O₉ provides a rich reservoir for hosting diverse magnetic and structural phases as a function of the metal ion M.