Study of the transport properties of La0.8Ba0.2MnO3/SrTiO3:Nd heterojunctions under reverse bias

Heterojunctions composed of P-type La0.8Ba0.2MnO3 and N-type Nd doped SrTiO3 are successfully fabricated via chemical solution deposition. Good rectifying property is obtained. Detailed studies of the transport properties under reverse bias show that above the metal-insulator transition temperature TMI, the Frenkel–Poole emission dominates the leakage current and the emission barrier height was extracted. When placed in magnetic field, the junctions show different transport behaviors below and above TMI. It shows negative magnetoresistive effect below TMI and positive one above TMI. This is explained by the phase separation mechanism and the band structure of manganites.