LCO/LAO film show a broad transition around $T_\textup{C} \approx 40$ K, as the arrow indicated in the inset of Fig. 2(c). The hysteresis loops at $T = 2$ K with saturation field of 30 KOe shown in Fig. 2(d) also confirm a FM state in LCO/LAO film. Finally, the LCO film on LSAT substrate exhibits similar behaviors to the LCO/LAO film with a Curie temperature of 75 K (not show here). It is noted that the in-plane lattice parameter of LAO, LSAT, and STO substrates are 3.810${\AA}$, 3.868${\AA}$, and 3.905${\AA}$, respectively. Thus, the Curie temperatures $T_\textup{C}$ of LCO film increases with the in-plane film lattice parameter, consistent with previous results [@Fuchs2008]. As shown in the insets of Fig. 2(b) and (d), all LCO films have similar low coercivity and remanence, indicating weak magnetic anisotropy in the epitaxial LCO films.

In order to check the insulating nature of deposited LCO films, we also carried out the measurements of electrical resistivity as a function of temperature. As shown in Fig. 3, though the LCO/STO exhibits a sharp FM transition, the electrical resistivity displays an extreme insulating state below 350 K, where the electrical resistivity is too large to be measured in the 