Fabrication and Transport Properties of DyMnO3/SrTi0.99Nb0.01O3 Heteroepitaxial Structures

Perovskite manganite (DyMnO3) films were fabricated epitaxially on SrTi0.99Nb0.01O3 single-crystal substrates by using a pulsed laser deposition technique. The films crystallized in orthorhombic structures, and the heteroepitaxial relationship between the films and the substrates was analyzed. The electrical transport properties reveal diodelike rectifying behaviors in the all-perovskite oxide structures over a wide temperature range (100 ∼ 340 K). The forward current increases exponentially with the increasing forward bias voltage, and the extracted ideality factors show distinct transport mechanisms in high- and low-positive regions. The built-in potentials were determined by using capacitance-voltage measurements at different frequencies. The results show the importance of temperature and applied bias in determining the electrical transport characteristics of heteroepitaxial oxide structures.