of the films was measured in Bruker icon atomic force microscope (AFM). The magnetic properties of the films were studied by using quantum-design magnetic properties measurement system (SQUID VSM-7 T). The measurements of transverse Hall resistance R$_{xy}$ and longitudinal resistance R$_{xx}$ were carried out in quantum-design physical properties measurement system with a rotating state (PPMS-9 T) at a temperature range of 2-300 K.

RESULTS AND DISCUSSION
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Structural characterization
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Figures 1(a)-(c) plot representative room temperature 2$\theta$-$\omega$ XRD scans of LCO films deposited on (001)-oriented LAO (top), LSAT (middle) and STO (bottom) single crystalline substrates, with other films showing similar patterns. No indication of impurities or misorientation was detected in the full range of 2$\theta$-$\omega$ scan (10-80 degree). The enlarged plot of (002) reflections are presented in the right panel of Figs. 1(a)-(c), where the arrows mark the reflection peak of LCO films. Clear Lauer oscillations indicate high quality and uniformity of epitaxial LCO films on LSAT and STO substrates. Whereas, no oscillation can be found on LAO substrate. One possible reason is that the mismatch of lattice parameters between LCO film and substrate is much larger on LAO substrate than on LSAT or STO substrate. The difference of 2$\theta$ 