Superconductivity in 5d transition metal Laves phase SrIr₂

Area of Science:

• Condensed Matter Physics
• Materials Science
• Superconductivity

Background:

• Laves phase materials are known for diverse physical properties.
• Iridium-based compounds often exhibit strong spin-orbit coupling effects.
• Understanding novel superconductors is crucial for technological advancements.

Purpose of the Study:

• To investigate the superconducting properties of the Laves phase compound SrIr2.
• To determine key superconducting parameters such as critical fields and penetration depth.
• To explore the influence of spin-orbit coupling on the material's physical characteristics.

Main Methods:

• Experimental measurement of superconducting transition temperature (Tc).
• Determination of lower and upper critical fields (µ0Hc1, µ0Hc2).
• Specific heat measurements to analyze electron-phonon coupling strength.
• Theoretical calculations incorporating spin-orbit coupling (SOC).

Main Results:

• SrIr2 is identified as a type-II superconductor with Tc = 5.9 K.
• Estimated superconducting parameters include µ0Hc1 ≈ 101 Oe, µ0Hc2(0) ≈ 5.9 T, ξ(0) ≈ 7.47 nm, λ(0) ≈ 237 nm, and κ(0) ≈ 31.7.
• Specific heat data (ΔC/γTc ≈ 1.71) indicate strong-coupling superconductivity, exceeding BCS theory predictions.
• Experimental results are well-reproduced by theoretical calculations including SOC.

Conclusions:

• SrIr2 is a strong-coupling superconductor with significant SOC effects.
• The study provides valuable insights into the superconducting mechanisms in Iridium-based Laves phases.
• The findings highlight the role of SOC in dictating the physical properties of SrIr2.