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arXiv · 2010.13445

Magnetic excitations in an ionic spin-chain system with a non-magnetic ferroelectric instability

K. Sunami·Y. Sakai·R. Takehara·H. Adachi·K. Miyagawa·S. Horiuchi·K. Kanoda
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Abstract

Cross-correlation between magnetism and dielectric is expected to offer novel emergent phenomena. Here, magnetic excitations in the organic donor-acceptor spin-chain system, TTF-BA, with a ferroelectric ground state is investigated by $^1$H-NMR spectroscopy. A nonmagnetic transition with a ferroelectric order is marked by sharp drops in NMR shift and nuclear spin relaxation rate $T_1^{-1}$ at 53 K. Remarkably, the analyses of the NMR shift and $T_1^{-1}$ dictate that the paramagnetic spin susceptibility in TTF-BA is substantially suppressed from that expected for the 1D Heisenberg spins. We propose that the spin-lattice coupling and the ferroelectric instability cooperate to promote precursory polar singlet formation in the ionic spin system with a nonmagnetic ferroelectric instability.

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K. Sunami, Y. Sakai, R. Takehara, H. Adachi, K. Miyagawa, S. Horiuchi, K. Kanoda. 2020-10-26. Magnetic excitations in an ionic spin-chain system with a non-magnetic ferroelectric instability. https://doi.org/10.1103/physrevresearch.2.043333

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