Anisotropic resistivity and electroresistance in epitaxial La0.3Pr0.4Ca0.3MnO3 thin films

The effects of anisotropic strain (AS) are considered in La0.3Pr0.4Ca0.3 MnO3 films produced by pulsed laser deposition on [001]-oriented NdGaO3 substrates via magnetic and resistivity measurements along with the two orthogonal in-plane directions. The anisotropic resistance is manifested with various degrees due to the different strengths of anisotropic strain that can be controlled with film thicknesses. The temperature-dependent resistivity was measured along with the two orthogonal directions. The anisotropic resistivity (AR) originated from different percolation paths in films and reached an extraordinary value of similar to 10(7)% for the film, with a thickness of 50 nm. On the other hand, the enhanced AR reveals that the AS induces electronic phase separation with ferromagnetic metallic entities' appearance with preferred orientation along (100) direction in an antiferromagnetic insulating background. Besides, we examined the effects of electric current on the resistivity of films. It is found that the application of larger currents results in a dramatic reduction of film resistance, and the extraordinary value of the electroresistance (similar to 97%) was obtained by increasing the current from 0.01 to 10 mu A. We attribute this behavior to the percolative channels with a width comparable to the mesoscopic phase-separated domains.

Automated summary

The effects of anisotropic strain on La0.3Pr0.4Ca0.3 MnO3 films were investigated. The anisotropic resistance was observed due to different strengths of anisotropic strain controlled by film thicknesses. The anisotropic resistivity originated from different percolation paths in the films and revealed electronic phase separation induced by anisotropic strain. Additionally, the resistivity of the films was found to be significantly reduced by applying electric currents.