The thickness of these films was measured using a stylus surface profilometer (Dektak 6M, Veeco Instruments Inc., USA). Prior to the XRD measurements, one of the FMO thin films was electrochemically lithiated to half of its theore-cal capacity (3.3 µAh/cm 2 ) 38,40 by charging it as the nega-ve electrode, with the LCO thin film on the opposite side of the substrate serving as the posi-ve electrode.