Abstract
We present a model compound for the ferromagnetic Heisenberg chain composed of the verdazyl-based complex . MO calculations indicate a predominant ferromagnetic interaction forming an ferromagnetic chain. The magnetic susceptibility and specific heat indicate a phase transition to an antiferromagnetic (AF) order due to the finite interchain couplings. We explain the magnetic susceptibility and magnetization curve above the phase-transition temperature based on the ferromagnetic Heisenberg chain. The magnetization curve in the ordered phase is described by a conventional AF two-sublattice model. Furthermore, the obtained magnetic specific heat reproduces the almost temperature-independent behavior of the ferromagnetic Heisenberg chain. In the low-temperature region, the magnetic specific heat exhibits a dependence, which is attributed to the energy dispersion in the ferromagnetic chain.
- Received 18 October 2018
DOI:https://doi.org/10.1103/PhysRevB.99.094418
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