Study of strongly correlated electron systems by means of angle-resolved thermal expansion measurements

To investigate novel ordering such as unconventional superconductor, multipole ordering, and hidden order, we developed an angle-resolved magnetostriction measurement system in the temperature range from 230mK to 40K. The dilatometer developed here allows a easy mounting of the sample without removing the dilatometer, and the sample shape is unimportant for the measurements. The relative sensitivity is better thanΔl/l=10^ for l=1mm. Applications to this system on the strongly correlated electron systems HoSb and CeRu_2Al_ are presented.