Study on the electrical transport properties of La2/3Ba1/3MnO3:Ag0.04/LaAlO3 (001) films

Abstract La 2/3 Ba 1/3 MnO 3 : wt%Ag x (LBMO:Ag x , x= 0.04) films were prepared on single crystalline (001)-orientated LaAlO 3 substrates by pulsed laser deposition technique. All the samples show along the (00 l ) orientation in rhombohedral structure with R 3 c space group. The surface roughness ( R a), insulator-metal transition temperature ( T p) and resistivity at T p ( ρ T p ) of the LBMO:Ag 0.04 films reached optimal values of 3.29 nm, 288 K and 0.033 Ω cm at 740 °C, respectively. The improvement of electrical transport properties in the films are attributed to the optimal growth temperature and Ag-doping improve the microstructure of the surfaces, grain boundaries (GBs) in connectivity and better crystallization. In addition, the electrical conduction behaviors can be well fitted with the grain/domain boundary, electron–electron and magnon scattering mechanisms in the ferromagnetic metallic region ( T T p), as well as with the adiabatic small polaron hopping mechanism in the paramagnetic insulating region ( T > T p).