Magnetic-field-induced quantum critical point in YbPtIn and YbPt0.98In single crystals

Detailed anisotropic (H‖ab and H‖c) resistivity and specific heat measurements were performed on on-line-grown YbPtIn and solution-grown YbPt0.98In single crystals for temperatures down to 0.4K and fields up to 140kG; H‖ab Hall resistivity was also measured on the YbPt0.98In system for the same temperature and field ranges. All these measurements indicate that the small change in stoichiometry between the two compounds drastically affects their ordering temperatures (Tord≈3.4K in YbPtIn and ∼2.2K in YbPt0.98In). Furthermore, a field-induced quantum critical point is apparent in each of these heavy fermion systems, with the corresponding critical field values of YbPt0.98In (Hcab around 35–45kG and Hcc≈120kG) also reduced compared to the analogous values for YbPtIn (Hcab≈60kG and Hcc>140kG).