Magnetotransport properties in thin films of charge-ordered materials

Thin films of Pr0.7Ca0.3MnO3, Nd0.5Ca0.5MnO3, and Nd0.5Sr0.5MnO3 have been fabricated by pulsed-laser deposition, and the magnetic and electrical transport properties of these films were compared with their bulk properties. All the films grow in the (101) direction on\ud LaAlO3(100). Electrical transport measurements carried out with and without magnetic field have shown d rho /dT <0 in these thin films. Application of a magnetic field has produced an increase in the conductivity of the films. Magnetization studies showed that Nd0.5Sr0.5MnO3 exhibits ferromagnetic behavior at 260 K and antiferromagnetic below 130 K. This is close to the bulk magnetic behavior of Nd0.5Sr0.5MnO3. Pr0.7Ca0.3MnO3 showed a ferromagnetic transition below 130 K while Nd0.5Ca0.5MnO3 remained paramagnetic down to low temperatures, showing a deviation from the magnetization exhibited by their respective bulks. Deviation in the properties of the thin films from the bulk solids is attributed to the growth of the films in a more symmetric structure