Possibility of transitions of fractional order and heat capacity of the one-dimensional Ising model
On the basis of exact solution it was concluded for the first time that the traditional one-dimensional Ising model (ID IM) has phase transitions (PT) of arbitrarily high order, including fourth-, fifth- and sixth-order phase transitions, according to the Baxter’s classification. Moreover, this model also exhibits PT’s of fractional order. It was rigorously proved that in the Baxter approach the order of a PT in 1D IM can be any real number that not less than the unit. Shows the Baxter formula for order of PT r=2- α false when Т <sub>С</sub> = 0, when it is replaced by the expression r=1- α. The final result is just for systems with any dimensionality space at zero temperature phase transition. We show further how fractional order of PT can be defined consistently.