The Angular Dependence of the Critical Current of $\hbox{BaCeO}_{3}$ Doped $\hbox{YBa}_{2}\hbox{Cu}_{3}\hbox{O}_{6+x}$ Thin Films

The angular dependencies of the critical current of BaCeO
₃
(BCO) doped YBa
₂
Cu
₃
O
_6+x
(YBCO) thin films grown with pulsed laser deposition (PLD) on SrTiO
₃
(001) were systematically investigated. The BCO concentration in the YBCO matrix was varied between 0-8 wt.%. Transmission electron microscopy confirmed that the 4% BCO containing sample has point-like, partly agglomerated BCO particles with diameter of 2.5 nm. The dopant degrades the crystal quality of YBCO but improves its in-field current carrying performance especially at low temperatures. The BCO addition affects the angular dependence of the critical current by broadening the B||ab-axis peak of YCBO but no c-axis peak is seen, which is contrary to BaZrO
₃
doped films made by PLD. Although the particles are point-like, it is found that a model featuring only isotropic pinning centers is not sufficient to describe the angular dependence of the samples where B||ab-axis of YCBO.