Magnetic Properties of a Mixed Spin-(1/2,5/2) Chain in (4-Cl-o-MePy-V)FeCl4

The magnetic properties of a mixed spin-(1/2, 5/2) chain produced in a charge-transfer salt (4-Cl-o-MePy-V)FeCl4 were investigated. The formation of a mixed spin-(1/2, 5/2) chain with a slight bond alternation was confirmed by molecular orbital calculations. An entire magnetization curve was observed until the point of saturation, which included a clear Leib-Mattis (LM) magnetization plateau and subsequent quantum phase transition toward the gapless Luttinger liquid phase. The magnetic susceptibility and specific heat further confirmed the formation of the LM ferrimagnetic state. A root T contribution was clearly observed in the low-temperature specific heat, which indicated the contributions of the low-energy magnon excitations in the LM ferrimagnetic state. Electron spin resonance analysis was used to evaluate the effective interchain couplings that resulted in the antiferromagnetic order and on-site biaxial anisotropy associated with the spin-flop transition. In addition, the effects of magnetic anisotropy on the low-energy magnon excitations in the LM plateau phase were evaluated.

Automated summary

The magnetic properties of a mixed spin-(1/2, 5/2) chain in a charge-transfer salt were investigated, confirming the formation of the chain and observing a clear LM magnetization plateau. The magnetic susceptibility and specific heat further confirmed the formation of the LM ferrimagnetic state.