Critical current and flux pinning in c‐axis oriented YBa2Cu3O7/PrBa2Cu3O7 superlattices

A magnetical critical current density J(c) of the order of 10(6) A/cm(2) at 4.5 K has been obtained in c-axis oriented YBa2Cu3O7/PrBa2Cu3O7 (YBCO/PBCO) superlattices with 24 Angstrom thick YBCO layer. The flux pinning force can be scaled as f(p) = alpha(1 - t)(m) h(p)(1 - h)(q), m = 3.5, p = 1.1, and q = 2.9 for YBCO(24 Angstrom)/PBCO(24 Angstrom) m = 3.4, p = 1.2, and q = 2.7 for YBCO(24 Angstrom)/PBCO(84 Angstrom). This approximate h(1 - h)(3) scaling behavior suggests a combined effect of tilt modulus C-44 and shear modulus C-66 of the flux line lattice (FLL), indicating that FLL executes both tilt and shear motion in the two superlattices. The interfacial flux pinning mechanism has also been discussed.