Comparative Raman scattering study of Ba₃MSb₂O₉ (M=Zn, Co and Cu)

• Published in: Физика низких температур
• Date: 2017
• Main Authors: Glamazda, A., Lemmens, P., Do, S.-H., Choi, K.-Y.
• Format: Article
• Language: English
• Published: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2017
• Subjects: К 70-летию со дня рождения С.Л. Гнатченко
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/129491
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: 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.

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.