Consider atD. Ising model of N sping at temp. where all splins are other. There will be with each spin flip 25. In a energy. aligned 11e to each few spins flip at temp. T is added.. energy configuration of N spins, rspins are flip, the the system, of the very lowe C is. E = NJ + 2YJ rHip spin energt gallsbin are lle is No. of configuration is NCY, & varies from a to N The partition fun" of the system is.