Flux pinning and flux creep in La2−xSrxCuO4 with splayed columnar defects

Abstract The effects of columnar defects with splayed configurations on flux pinning and flux creep were investigated experimentally. Parallel columnar defects and splayed columnar defects were introduced into specimens of La 2− x Sr x CuO 4 by high-energy heavy-ion irradiation. A large enhancement of the flux pinning and the critical current density J c due to the splayed columnar defects was observed. At temperature T H =0.1 T, the effective pinning potential U 0 of a specimen with splayed columns was larger than that of a specimen with parallel columns. On the other hand, at 15 K≤ T ≤30 K and H =0.1 T, U 0 of a specimen with splayed columns was smaller than that of a specimen with parallel columns.