Record critical current density in bulk MgB2 using carbon-coated amorphous boron with optimum sintering conditions

29th International Symposium on Superconductivity

Muralidhar, M.^1 ; Higuchi, M.^1 ; Diko, P.^2 ; Jirsa, M.^3 ; Murakami, M.^1

Superconducting Material Laboratory, Graduate School of Science and Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo

135-8546, Japan^1

Institute of Experimental Physics SAS, Watsonova 49, Kosice

SK-04353, Slovakia^2

EInstitute of Physics CAS, Na Slovance 2, Praha 8

CZ-18221, Czech Republic^3

关键词: Amorphous boron;    Carbon content;    Carbon-encapsulated;    Current performance;    Sintering condition;    Sintering temperatures;    Synthesis and characterizations;    Technical applications;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/871/1/012056/pdf
DOI  :  10.1088/1742-6596/871/1/012056

来源: IOP

【 摘 要 】

We report on the synthesis and characterization of a sintered bulk MgB2material produced at an optimized sintering temperature with a varying content of carbon-encapsulated amorphous boron. A series of MgB2bulks was prepared with 0%, 1.5%, 2.8%, 7.3%, 12% and 16.5% of carbon-encapsulated boron. In the samples with 12% of carbon-encapsulated boron, Mg and MgB2C2formation was observed. Tcwas around 38.4 K for the pure MgB2and decreased with increasing carbon content up to 25 K for 16.5 % of carbon-encapsulated boron. The highest Jcvalues of 470 kA/cm2and 310 kA/cm2, in the self-field and 1 T, respectively, were achieved at 20 K, in the MgB2sample with 1.5% of carbon-encapsulated boron. It proved that the optimized sintering conditions together with the appropriate amount of the carbon-coated boron were able to bring critical current performance of bulk MgB2material up to the level necessary for real technical applications.