Experimental Study of Quantum Statistics for theS=12Quasi-One-Dimensional Organic Ferromagnet

Using a genuine organic ferromagnetic radical crystal (${\mathrm{C}}_{10}$ ${\mathrm{H}}_{10}$ ${\mathrm{N}}_4$SCl) which was synthesized recently, we experimentally examined the results of quantum statistics for a one-dimensional Heisenberg ferromagnet with spin $S=\frac{1}{2}$. The characteristic thermodynamical properties expected of the most isotropic Heisenberg system, such as magnetic susceptibilities with the critical index of $\gamma =2.0\mathrm{}$ and field dependence of magnetic heat capacity, are herein revealed.