Superconductivity in (110) PrBa₂Cu₃O7-δ Thin Films Pseudomorphically Grown on (110) YBa₂Cu₃O7-δ Single Crystal Substrates

We report on superconductivity in (110) oriented PrBa 2 Cu 3 O 7-δ films pseudomorphically grown on (110) YBa 2 Cu 3 O 7-δ (YBCO) single crystal substrates. The vertical 4-probe measurements for (110) PrBa 2 Cu 3 O 7-δ / YBa 2 Cu 3 O 7-δ bilayers show clearly two superconducting transition steps associated with two different T c 's of 92.0 K of YBa 2 Cu 3 O 7-δ , 89.9 K for 30 nm thick PrBa 2 Cu 3 O 7-δ and 75.5 K for 220 nm thick PrBa 2 Cu 3 O 7-δ . The non-substitutional “regular” Pr 1+ x Ba 2- x Cu 3 O 7-δ ( x =0.0) without any interchange between Pr atoms and Ba atoms will show superconductivity by the same mechanism with other YBCO families.