Low Temperature Magneto-transport Measurements on Multilayered Manganite Films

We have performed out-of-plane resistance measurements on a micro-fabricated multilayered manganite thin film structure down to 50 mK. The structure is composed of a 26 nm thick (La$_{0.4}$Pr$_{0.6})_{0.67}$Ca$_{0.33}$MnO$_{3}$ (LPCMO) film on top of a 60 nm thick La$_{0.67}$Ca$_{0.33}$MnO$_{3 }$(LCMO) layer grown on an (110) NdGaO$_{3}$ (NGO) substrate. Two gold electrodes were deposited on the LPCMO layer and the exposed LPCMO layer was then etched by ion plasma etching technique. We observed an upturn in resistance below 30 K for various current excitations ranging from 0.2 to 100 $\mu $A. Based on the electric and magnetic field dependence of the resistance, we attribute the upturn to the disorder-induced static phase separation of the LPCMO thin film at low temperature.