Studies on the Weak Itinerant Ferromagnet SrRuO3 under High Pressure to 34 GPa

TL;DR

This study investigates how the ferromagnetic Curie temperature of SrRuO3 decreases under high pressure up to 17.2 GPa, with no superconductivity observed up to 34 GPa, and examines structural stability and bond angle changes.

Contribution

It provides detailed measurements of Tc suppression under high pressure and reports no superconductivity or structural phase transition up to 34 GPa.

Findings

Tc decreases linearly with pressure at -6.8 K/GPa

No superconductivity above 4 K up to 34 GPa

Structural stability maintained with no phase transition

Abstract

The dependence of the Curie temperature Tc on nearly hydrostatic pressure has been determined to 17.2 GPa for the weak itinerant ferromagnetic SrRuO3 in both polycrystalline and single-crystalline form. Tc is found to decrease under pressure from 162 K to 42.7 K at 17.2 GPa in nearly linear fashion at the rate dTc/dP = -6.8 K/GPa. No superconductivity was found above 4 K in the pressure range 17 to 34 GPa. Room-temperature X-ray diffraction studies to 25.3 GPa reveal no structural phase transition but indicate that the average Ru-O-Ru bond angle passes through a minimum near 15 GPa. The bulk modulus and its pressure derivative were determined to be B =192(3) GPa and B' = 5.0(3), respectively. Parallel ac susceptibility studies on polycrystalline CaRuO3 at 6 and 8 GPa pressure found no evidence for either ferromagnetism or superconductivity above 4 K.