La(Sr,Pb)MnO3 Thin Films through Solution Techniques

Thin films of (La 0.9 Sr 0.1 )MnO 3 have been deposited using a citrate−ethylene glycol method. Si (100) substrates yield polycrystalline films, whereas MgO (100) substrates favor the nucleation of textured films. However, the rough calcination of organics results in a granular morphology with insulating grain boundaries. Sintering can be strongly enhanced by addition of small amounts of lead oxide. When substituted for strontium, lead does not drastically affect the physical properties of the perovskite phase, but allows the formation of a percolative conduction path. Conductive films have been obtained through heat-treatment at temperatures as low as 600 °C. They show a magnetoresistance effect (Δρ/ρ 0 ) of 65% at 175 K in fields up to 8 T.