بررسی اثر کمبود اکسیژن، گذار فاز ساختاری ارتورمبیک‌ - تتراگونال‌ و ساختار نوار انرژی در ترکیب YBa2Cu3O7-& delta

  Obtaining the superconductor samples or mainly, structural phase controlling in 123 systems is a matter of special importance. As decreasing of oxygen in this structure has special effects, and mainly causing structural phase transition, by investigating the structure and thermal analysis of the system, tetragonal-orthorhombic structural phase transition was observed and optimum contents of structural phase transition temperature and oxygen were gained (ζc=630±5°c ) and ( 7-δcΞ6.6), respectively, that are in good agreement with others’ work.   In addition by band structure and density of states calculations of we gained the equilibrium position, the role and contribution of ions, especially oxygen, in total system’s density of state. It shows that the conductivity of orthorhombic phase is more in compare with tetragonal phase in normal states of 123 systems.