In-Plane Anisotropy of Transport Property in BaTbO3-Doped SmBa2Cu3Oy Films
BaTbO3 (BTbO) is one of artificial pinning center ma-terials and forms thick rectangular nanorods with diameters of ∼20 nm when it is doped high. We expected that the rectangular na-norods would produce in-plane anisotropy of flux pinning. In this study, we investigated in-plane anisotropy of transport properties in BTbO-doped SmBa2Cu3Oy (SmBCO) films. SmBCO thin films with various contents of BTbO were fabricated by using a pulsed laser deposition method. To investigate the in-plane anisotropy, the criti-cal current density Jc was measured at 77 K, 0-9 T, and Φ = 0º and 45º, where Φ was defined as an in-plane angle from the a or b-axes of SmBCO. To fix the direction of current in the films, the micro-bridges were fabricated with different Φ = 0º and 45º by using the laser etching technique. As a result, Jc at Φ = 0º was higher than one at Φ = 45º in the films with BTbO contents of 12.0 and 20.0 vol.% at 77 K and at fields of 5 T or more. The anisotropy of Jc in high fields for current directions was possibly explained by the rectangular shape of the BTbO nanorods.