Hall effect of the quinquevalent ion-doped La0.9Sb0.1MnO3(LSbMO)film,with strong magnetic-resistive correlation,which was believed to be an electron-doped manganite,was experimentally studied,and a positive normal Hall coefficient was observed below the Curie temperature,which indicated that the system was hole doped.These observations might be attributed to the presence of excessive oxygen in the film.The resistivity of the film increased overall and the metal-semiconductor transition shifted to a lower temperature after removing excessive oxygen by vacuum annealing.These results implied that the magnetic-resistive correlation in the LSbMO film was attributed to the interaction between Mn3+ and Mn4+ ions,instead of that between Mn2+ and Mn3+ ions.
Interfacial barrier is a key factor that determines the performances of heterojunctions.In this work,we study the effect of manganite film thickness on the effective interfacial barrier for La 0.67 Sr 0.33 MnO 3 /Nb:SrTiO 3 junctions.The barrier is extracted from the forward current-voltage characteristics.Our results demonstrate that the barrier decreases gradually from ～0.85 eV to ～0.60 eV when the film thickness decreases from 150 nm to 2 nm.The overall value of the barrier is only about 50% of the corresponding one determined from the photovoltaic effect.
