Low-temperature thermodynamics of the classical frustrated ferromagnetic spinchain near the ferromagnet-helimagnet transition point is studied by means ofmapping to the continuum limit. The calculation of the partition function andspin correlation function is reduced to quantum problem of a particle inpotential well. It is shown that exactly at the transition point thecorrelation length behaves as $T^{-1/3}$ and the magnetic susceptibilitydiverges as $T^{-4/3}$ in the low-temperature limit. Corresponding numericalfactors for the correlation length and the susceptibility is calculated. It isshown that the low-temperature susceptibility in the helical phase near thetransition point has a maximum at some temperature. Such behavior as well asthe location and the magnitude of the maximum as a function of deviation fromthe transition point are in agreement with that observed in several materialsdescribed by the quantum $s=1/2$ version of this model.
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机译：通过映射到连续极限，研究了经典的受挫铁磁自旋链在铁磁体-直升机磁体转变点附近的低温热力学。将分配函数和自旋相关函数的计算简化为粒子势阱的量子问题。结果表明，恰好在过渡点处，相关长度在低温极限下表现为$ T ^ {-1/3} $，磁化率则变化为$ T ^ {-4/3} $。计算了相关长度和磁化率的相应数值因子。结果表明，在一定温度下，转变点附近的螺旋相的低温敏感性最高。这种行为以及最大值的位置和大小作为与转变点之间偏差的函数，与在该模型的量子$ s = 1/2 $版本描述的几种材料中观察到的一致。
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