Coupling Between Magnetic and Thermodynamic Properties in RRh_2Si_2 (R = Dy, Ho)

Single crystals of DyRh2Si2 and HoRh2Si2 were investigated by thermal expansion and magnetostriction. The different types of magnetic order can clearly be seen in these measurements, particularly the canting of the moments away from the crystallographic c direction below about 12 K and the spin flip for magnetic field applied along the c direction. For HoRh2Si2, an additional transition just below TN is analyzed by means of the Gr & uuml;neisen ratio and is likely caused by a change in the magnetic structure. Our results nicely corroborate findings from other magnetic and thermodynamic measurements on these materials and provide further evidence suggesting the formation of magnetic domains.