Print version ISSN 0366-6913
CASTRO, R. H. R.; HIDALGO, P.; GOUVEA, D. and NAVROTSKY, A.. Surface energy of pure and doped tin oxide. Cerâmica [online]. 2009, vol.55, n.336, pp.342-348. ISSN 0366-6913. http://dx.doi.org/10.1590/S0366-69132009000400002.
Calorimetry has been proved to be an important tool to control and understand the behavior of nanostructured systems. This is basically because of the recent surface energy measurements reported in the literature by high-temperature calorimetry. That is, since in nanosized systems the surface accounts for a larger part of the total atoms, knowing their energy is of main importance to achieve a desired control. However, calorimetric procedures to measure the surface energy are relatively complex and, if it were possible to estimate the surface energy using alternative techniques, this could have giant impacts in the nanoscience and nanotechnology. In this work, the anhydrous surface energy of SnO2 is presented to be 3.2 J/m2 measured by drop solution calorimetry corrected by water adsorption. After this, a discussion of the effect of some additives in the SnO2 nanostructure is presented. It is established that additives that form surface excess can decrease the surface energy in addition to modifications in the diffusion parameters. Considering a particle growth model, we could calculate the surface energy of SnO2 doped with Mg, Fe, Cr, and Ni.
Keywords : SnO2; nanoparticles; dopants; surface energy.