Diamagnetic Properties of Nd-Ce-Cu-O Superconducting Thin Films with Electron Carriers

The diamagnetic properties of superconducting Nd-Ce-Cu-O films with n-type carriers were studied by an rf SQUID susceptometer. The specimen indicates remanent magnetization up to 25 K which is higher than the zero-resistance temperature by 3 K. The critical current density was calculated by Bean’s formula to be 0.73× 10⁶ A/cm² at 4.2 K. Although the transition temperature is relatively low, very strong magnetic relaxation was observed for this specimen. In the flux creep model, the activation energy was estimated to be about 0.01 eV which is much smaller than ErBaCuO or TlBaCaCuO film.