Improved electrical properties of La 2/3 Ba 1/3 MnO 3 :Ag 0.04 thin films by thermal annealing

La 2/3 Ba 1/3 MnO 3 :Ag 0.04 (LBMO:Ag 0.04 ) thin films were prepared on single crystalline (001)-orientated LaAlO 3 substrates by pulsed laser deposition technique. Thermal annealing with temperatures of 780, 800 and 820 °C has been investigated to improve electrical properties of the films. All the samples are shown along the (00 l ) orientation in rhombohedral structure with R3 c space group. With thermal annealing temperature increasing, insulator–metal transition temperature ( T p ) and resistivity at T p ( ρ_T_p ) of the epilayer reach optimal value of 288 K and 0.03 Ω·cm, respectively. The electrical properties improvement of the LBMO:Ag 0.04 films is due to an improved film crystallization, oxygen balance and photon scattering suppression. The fitting curves show that the region of ferro-magnetic metallic (FM, T < T p ) is fitted with grain/domain boundary, electron–electron and magnon scattering mechanism, as well as the region of para-magnetic insulating (PI, T > T p ) is fitted with adiabatic small polaron hopping mechanism.