Pressure-induced Change in Temperature Coefficient of Electrical Resistivity in CeCuAs₂

Abstract

The intermetallic compound, CeCuAs₂, crystallizing in a HfCuSi₂-type tetragonal structure, has recently been shown to exhibit a negative temperature (T) coefficient of electrical resistivity (ρ) in the entire T-range of investigation (45 mK to 300 K). Here, we report that an application of external pressure (up to 10 GPa) profoundly influences ρ(T) behavior, reversing the sign of dρ⁄dT at pressures above 8 GPa, presumably arising from increasing 4f hybridization or changes in pseudo-gap. Such a behavior is uncommon among Ce-based intermetallic compounds.