  Nano particles of pure ZnO, pure SnO$_2$, and nanocomposites of ZnO/SnO$_2$
were synthesized using microwave hydrothermal technique starting from aqueous
solutions. Nanocomposites with different molar ratios of ZnO and SnO$_2$ were
prepared. Structural, morphological and optical properties of these samples
were investigated using XRD, SEM and UV-visible technique, respectively. The
single phases of ZnO and SnO$_2$ could be fabricated according to XRD patterns.
The relative intensities of different XRD peaks in different nanocomposite
samples were different by indicating that there are some preferred orientations
in different samples. In XRD patterns of nanocomposites, peaks of both pure ZnO
and pure SnO$_2$ samples appear. Particle size was in the range of nano-range
according to SEM micrographs. Optical bang gap was measured by UV-visible
spectrometer. Optical band gaps of nano composites are less than those of pure
ZnO and SnO$_2$ due to the increase of particle size.
