Effect of La Doping on Microstructure and Critical Current Density of MgB2

Abstract

In the present study, La-doped MgB_2 superconductors with different doping level (Mg1-xLaxB2; x=0.00, 0.01, 0.03 & 0.05) have been synthesized by solid-state reaction route at ambient pressure. Effect of La doping have been investigated in relation to microstructural characteristics and superconducting properties, particularly intragrain critical current density (Jc). The microstructural characteristics of the as synthesized Mg(La)B2 compounds were studied employing transmission electron microscopic (TEM) technique. The TEM investigations reveal inclusion of LaB6 nanoparticles within the MgB2 grains which provide effective flux pinning centres. The evaluation of intragrain Jc through magnetic measurements on the fine powdered version of the as synthesized samples reveal that Jc of the samples change significantly with the doping level. The optimum result on Jc is obtained for Mg0.97La0.03B2 at 5K, the Jc reaches ~1.4x107A/cm2 in self field, ~2.1 x 106A/cm2 at 1T, ~2.5 x 105A/cm2 at 2.5T and ~1.8 x 104 A/cm2 at 4.5T. The highest value of intragrain Jc in Mg0.97La0.03B2 superconductor has been attributed to the inclusion of LaB6 nanoparticles which are capable of providing effective flux pinning centres.

References in corpus (11)

• Strongly linked current flow in polycrystalline forms of the new superconductor MgB2
• Enhancement of the critical current density and flux pinning of MgB2 superconductor by nanoparticle SiC doping
• Thermodynamic and Transport Properties of Superconducting $M{g}^{10}{B}_2$
• Superconducting Properties of MgB2 Bulk Materials Prepared by High Pressure Sintering
• Enhancement of the high-field critical current density of superconducting MgB2 by proton irradiation
• An Overview of the Basic Physical Properties of MgB${}_2$
• Neutron Irradiation of MgB2 Bulk Superconductors
• Enhancement of Critical Current Density in low level Al-doped MgB2
• Magnetization studies on superconducting MgB${}_2$ - lower and upper critical fields and critical current density
• Titanium additions to MgB2 conductors
• The influence of structural defects on intra-granular critical currents of bulk MgB2

Cited by in corpus (3)

• Prospects for Improving the Intrinsic and Extrinsic Properties of Magnesium Diboride Superconducting Strands
• High critical current density and improved flux pinning in bulk MgB2 synthesized by Ag addition
• Enhancement of flux pinning and high critical current density in graphite doped MgB2 superconductor