Abstract:
In this work we analyzed the model by M. A. Chuev recently published [JETP Letters 85, 611 (2007)]. Near the blocking temperature we show that the anisotropy corrections always lead to a lower magnetization than the equilibrium value, contrary to the findings in Chuev's work. Also we show that the asymptotic high-temperature limit of Chuev's model is not in agreement with the expected thermodynamic limit. Moreover, even at low-temperature only a careful implementation of this theory can guarantee arriving to the correct result, avoiding some wrong conclusions in Chuev's work.