The goal of this research is to study the elasto-plastic properties of La-Cr-O thin films deposited by RF-magnetron sputtering on stainless steel interconnect materials after annealing at high temperatures in air. Elastic modulus, hardness and yield pressure derived from nanoindentation data are reported for thin films in different structural states. The amorphous film has an estimated elastic modulus of 174 GPa. The moduli of annealed films are calculated to be 150, 185 and 120 GPa after annealing at 500 degrees C, 600 degrees C and 800 degrees C, respectively. The film annealed at 800 degrees C has the lowest hardness and is dramatically different from the other structural states due to formation of the nanoporosity. The amorphous film and the films annealed at 500 degrees C and 600 degrees C both have hardness of 14 GPa, which is close to the value estimated by modeling. (c) 2006 Published by Elsevier B.V.