Ar Ion Implantation Induced T_c Degradation of YBa₂Cu₃O_7-x Thin Films

The Ar ion implantation induced changes of structure and transport properties of YBa₂Cu₃O_7-x thin films were studied as a function of fluence. Both the zero resistance temperature T_c and the critical current density Jc decrease rapidly with fluence, however, the transition temperature onset almost remains constant at low fluences. At dose of 1.2x10¹³Ar/cm², the sample has a metal to semiconductor phase transition. When the fluence further increases, a crystalline to amorphous phase transition occurs, and the sample becomes insulator.