OF SYNTHESIZED SnO 2 NANOPARTICLES.Tin oxide (SnO 2 ) is widely used in industry as raw material for electronic devices, plating of different types of materials, for dyes and pigments, for electroplating, heterogeneous catalysis, etc.In this work SnO 2 was obtained by a controlled precipitation method with special attention to the effects the tin precursor has on the microstructure of the final product.The most appropriate pH for obtaining SnO 2 with the rutile structure as the main phase is 6.25 for SnCl 2 and 6.40 for SnSO 4 .After heat treatment at 600 °C, particles of nanometric order (~10 -30 nm approx) were obtained.The characterization of the solid phase was made by X-ray diffraction (XRD), thermal analysis (DTA/TG), transmission electron microscopy (TEM) and Fourier transformed infrared spectroscopy (FTIR).