Surface morphology and magnetic properties in Pr0.7Sr0.3MnO3 layer grown on charge-ordered La0.5Ca0.5MnO3 layer

• Pr0.7Sr0.3MnO3/La0.5Ca0.5MnO3 film was grown on SrTiO3 by pulsed laser deposition.
• Large particulates at surface lead to the variation of crystalline structure.
• These particulates reduce the ferromagnetism and enhance the exchange bias field.
• An antiferromagnetic structure is formed at surface, causing the exchange bias.

We report magnetic behaviors in Pr0.7Sr0.3MnO3 (PSMO) layer grown on charge-ordered La0.5Ca0.5MnO3 (LCMO) layer. PSMO/LCMO bilayer film was prepared by pulsed laser deposition on SrTiO3 (001) substrate. Large particulates at the surface of PSMO layer impart inhomogeneous composition in film, resulting in the variation of film's crystalline structure. We find an exchange bias (EB) in the bilayer film with relative roughness and inhomogeneous surface, whereas smooth and homogeneous surface does not lead to an EB effect. It is believed that an antiferromagnetic structure is formed in the inhomogeneous PSMO layer, which causes the EB effect in this system. The present results are discussed and possible explanations are provided based on the random-field model of EB and the related research results.