• Progress in Superconductivity and Cryogenics
• /
• v.25 no.3
• /
• pp.22-27
• /
• 2023

Magnetic properties of MgB₂ superconducting powder were investigated. M(H), the magnetic field H dependence of magnetization M, was measured and analyzed using a PPMS instrument. The MgB₂ superconducting powder showed high critical current density J_c > ~ 10⁷ A/cm² and clean limit superconducting properties. The equilibrium magnetization M_eq properties of MgB₂ powders exhibiting various superconducting properties were studied. We find that the equilibrium magnetization M_eq(H) properties of MgB₂ powders showing conventional BCS properties deviate from the predictions of the standard local-London theory at temperatures below T = 19 K and are in good agreement with the generalized nonlocal-London theory. Nonlocal-London analysis was used to determine and analyze the nonlocal parameters. The temperature dependence of the London penetration depth values λ(T) was studied.