  Thermal expansion, or dilation, is closely related to the specific heat, and
provides useful information regarding material properties. The accurate
measurement of dilation in confined spaces coupled with other limiting
experimental environments such as low temperatures and rapidly changing high
magnetic fields requires a new sensitive millimeter size dilatometer that has
little or no temperature and field dependence. We have designed an ultra
compact dilatometer using an atomic force microscope (AFM) piezoresistive
cantilever as the sensing element and demonstrated its versatility by studying
the charge density waves (CDWs) in alpha uranium to high magnetic fields (up to
31 T). The performance of this piezoresistive dilatometer was comparable to
that of a titanium capacitive dilatometer.
