Low-temperature magnetic structure and electron paramagnetic resonance properties of the quasi-one-dimensional S = 1/2 Heisenberg helimagnet Cu$Cl_{2}$ ⋅ 2 N$C_{5}$$H_{5}$

A. Ponomaryov (1) , L. Zviagina (1, 2) , J. Wosnitza (1) , M. Thede (3) , E. Ressouche (4) , K. Yu. Povarov (3) , A. Zheludev (3) , C. Landee , S. Zvyagin (1)

1 Dresden High Magnetic Field Laboratory
2 TU Dresden - Technische Universität Dresden = Dresden University of Technology
3 Laboratory for Solid State Physics [ETH Zürich]
4 MDN - Magnétisme et Diffusion Neutronique

We present results of electron paramagnetic resonance (EPR) and neutron-diffraction studies of Cu$Cl_{2}$ ⋅ 2 N$C_{5}$$H_{5}$, which is regarded as one of the best known uniform spin-1/2 Heisenberg antiferromagnet chain systems. We reveal that at $T_{N}$=1.12 K, Cu$Cl_{2}$ ⋅ 2 N$C_{5}$$H_{5}$ undergoes the transition into the magnetically ordered spiral state with Q=(0.5,0.4,0.5) r.l.u. It was shown that the zigzag interchain interactions result in a noticeable geometrical frustration, also affecting the ordered moment per $Cu^{2+}$ and EPR properties, including the angular dependence of the linewidth. The temperature dependencies of the EPR parameters are discussed.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

A. Ponomaryov, L. Zviagina, J. Wosnitza, M. Thede, E. Ressouche, et al.. Low-temperature magnetic structure and electron paramagnetic resonance properties of the quasi-one-dimensional S = 1/2 Heisenberg helimagnet Cu$Cl_{2}$ ⋅ 2 N$C_{5}$$H_{5}$. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2017, 95 (19), ⟨10.1103/PhysRevB.95.195125⟩. ⟨hal-01937605⟩