are synthesized by combining two or more classes of
materials with very different properties so as to exploit
the beneficial properties of both of them. For example
if one wishes to exploit the strength of a ceramic material
and the ductility of a metallic material, a metal-ceramic
composite if made would have better strength than the
metallic component and better ductility than the ceramic
component. The image in the figure is a
composite made of crystalline nanoparticles and an
amorphous or glassy matrix.
atomic force microscope (AFM) used to image the
surface of this composite has of late become a very
common tool to study the surfaces of materials at the
nanoscale along with the scanning electron microscope.
Many variations of surface scanning microscopy are now
available and they are not only used to image surface
topography but also used to probe thermal, mechanical,
electronic, magnetic and dielectric properties of materials
at the nanoscale. In its simplest form such a microscope
uses a very sharp tip (radius of curvature of about
20 nm or less) that is moved with or without contact
over the surface to be studied using suitable mechanisms.
The application of thermal, electrical or magnetic fields
through the tip using suitable contacts helps probe
matter for the corresponding properties at the nanoscale.