Pressure effects in PrT2B2C (T = Co, Ni, Pt): Applied and chemical pressure

Abstract

AbstractHigh pressure electrical resistivity ρab measurements on intermetallic Pr(Co, Ni, Pt)2B2C compounds were performed down to 2 K. At ambient pressure the $\rho _{ab} (T)$ curves for the non‐superconducting Pr(Co, Ni)2B2C compounds exhibit magnetic correlations at about 10 and 4 K, respectively. At low temperatures, PrCo2B2C shows a large spin‐dependent electron scattering in comparison to PrNi2B2C. Under applied pressure, the magnetic scattering tends to be suppressed more effectively in PrCo2B2C than in PrNi2B2C. The low‐temperature behavior of $\rho _{ab} (T,P)$ for PrNi2B2C and PrCo2B2C suggests a spin fluctuation mechanism. On the other hand, the PrPt2B2C compound shows superconductivity at about 6 K and under pressure its superconducting transition temperature tends to be degraded at a rate ${\rm d}T_{{\rm c}} /{\rm d}P = {-} 0.34\;{\rm K/GPa}$, as expected in compounds with transition metals. The experimental results in Co‐, Ni‐, and Pt‐based compounds are analyzed from the point of view of the external and chemical internal pressure effects.