The thickness dependence of the effect of pressures on magnetic and electronic properties of thin films of La2/3Ca1/3MnO3

The discovery of the colossal magnetoresistance and pressure effects introduced new questions concerning the complex interplay among lattice structure, magnetism, and transport in doped perovskite manganites. To observe the interplay between the effect of pressure and strain due to the substrate in the La2/3Ca1/3MnO3 compound, we produced epitaxial films with the thickness varied between 20 and 100 nm on SrTiO3 substrates, using the pulse laser deposition technique and under the same epitaxial growth conditions. We measured magnetic transition temperature TC and resistivity ρ, as a function of pressure up to 8 kbar. Using these results, the dependence of bond compression on pressure, and the lattice distortion induced by the substrate, are discussed. We also report a universal behavior from the plot of d ln TC/dP and dρ/dP versus TC for these films, as well as previously published results on ceramic and thin films of this compound.