Terahertz Vibrational Dynamics and DFT Calculations for the Quantum Spin Chain Linarite, PbCuSO4(OH)2
Publication Name
Journal of Physical Chemistry A
Abstract
The low-dimensional quantum-magnet, linarite, PbCuS4(OH)2, has been investigated using terahertz (THz) spectroscopy coupled with detailed density functional theory (DFT) calculations in order to explore the effects of the temperature on its lattice vibrations. Linarite is characterized by largely isolated CuO chains propagating along the crystallographic b-axis, which at very low temperatures are responsible for exotic, quasi-1D magnetism in this material. To better understand the synergy between the structural bonds and lattice oscillations that contribute to these chains, polarized THz spectroscopic measurements were performed. Consolidating these results with detailed DFT calculations has revealed that the anisotropic vibrational motion for the THz modes is correlated with extreme motion associated with the crystallographic b-axis. An unexpected feature observed in the infrared spectrum is attributed to subtle lattice distortions which break the centro-symmetry in linarite at high temperatures. This phenomenon has not previously been observed in linarite and likely results from anharmonicity in lattice oscillations.
Open Access Status
This publication may be available as open access
Volume
128
Issue
10
First Page
1767
Last Page
1775
Funding Number
P32404–N27
Funding Sponsor
Austrian Science Fund