NBCO films (~2000 Å) prepared by the pulsed laser deposition technique were irradiated by (200 MeV) Au⁺¹⁴ ions. Detailed magnetization measurements were performed using a SQUID magnetometer. A broad, diffused fish tail peak (FTPE) in the J_c(H) curve and a plateau (instead of a Gaussian peak) in the F_p(H) curve (both around the matching equivalent field) are two notable features. We outline and illustrate their various implications with respect to vortex pinning in the framework of theoretical models and suggest that the swift heavy ion irradiation (SHI) can cause a Mott insulator-like phase transition.