earticle

영어

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 Jc > ∼ 107 A/cm2 and clean limit superconducting properties. The equilibrium magnetization Meq properties of MgB2 powders exhibiting various superconducting properties were studied. We find that the equilibrium magnetization Meq(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 (T) was studied.