Comparative studies on superconductivity in Cr₃Ru compounds with bcc and A15 structures

Area of Science:

• Condensed Matter Physics
• Materials Science
• Superconductivity

Background:

• Chromium (Cr) compounds exhibit dual localization and itinerancy due to 3d orbital electrons, influencing magnetic and conductive properties.
• Understanding the interplay of electron correlation, magnetism, and superconductivity in transition metal alloys is crucial for materials design.

Purpose of the Study:

• To investigate the physical properties of Cr3Ru compounds in body-centered cubic (bcc) and A15 crystal structures.
• To explore the superconducting mechanisms, electron correlation effects, and pressure response in these Cr-based alloys.

Main Methods:

• Experimental characterization using resistivity, magnetization, and specific heat measurements.
• Analysis of superconducting transitions, magnetic fluctuations, and electron correlation using Wilson ratios.
• Investigation of pressure effects on critical temperatures (Tc).

Main Results:

• Superconducting transitions observed at 2.77 K (bcc) and 3.37 K (A15), with high residual resistivity and moderate pairing strength (s-wave gaps).
• Evidence of antiferromagnetic spin fluctuations and a pronounced second peak effect in magnetization hysteresis for the bcc phase.
• Moderate electron correlation effects (Wilson ratios ~3.8) and pressure-induced enhancement of Tc observed in both phases.

Conclusions:

• Cr3Ru compounds in bcc and A15 structures display unique superconducting and normal state characteristics.
• The findings suggest a complex interplay between electron correlation, magnetism, and superconductivity in these Cr-based alloys.
• Further research into these materials could lead to novel applications in condensed matter physics and materials science.