Size effect on z igzag spin couplin g interaction in pr esence o f magnetic field for ۱-D Ising model o f Nanosys tem

Many physico-chemical systems can be represented by a lattice arrangement of molecules with including nearest-neighbor interactions appr oximately.T he simple st versionof this theory is the so-called "Ising model" . Ising model is able to explain many pro lems in physics and chemistry [۱].۱- D Ising mo del is much easier to be treated th eoretically than ۲- and ۳-D ones[۲-۳]. [(Tp) Fe(CN)۳ Mn(۵-MeOsalen). ۲CH ۳OH]n [ T p- = hydr otris(pyrazolyl)borate and ۵- MeOsalen۲-= N ,N'-ethylenebis(۵-metho xysalicylid neiminate)] is one of several co mpounds that pro vide the ۱-D zigza g chain[۴]. In this work we calculate partition function of Ising model with zigzag spin coupli ng interaction.With the partition function of such mode l we can c alculate its thermodynamic properties. To best of our knowle dge,size effect on ۱-DIsing mode l with zigzag spin coupling inter action in presence of mag netic field are explored . We investigate spin coupling interaction and magnetic field effect on finite size free energy ofthis mod el . Analytical expres sion for finite size free en ergy , and bulk free energy is derived for even , odd size of both ferroma gnetic (FF) and ferromagnetic -antiferr omagnetic (FA) zigz ag spin coupling interaction . Deviation of free energy of finite size of spin array from its bulk limit is investig ated for FF and FA spin chain as a function of ratio of magnetic fi eld to spin coupling interaction "f " and ratio of zi gzag spin c oupling "n" (competiti on factor).

کلیدواژه ها:

Finite size free energy ، Ising model ، Nanosystems ، Transfermatrix