The paper presents fabrication and characterization of spark plasma sintered textured(001) MgB_(2)with a record degree of orientation of about 40% and 16% by high-energy ultra-sonication and slip casting in high magne...The paper presents fabrication and characterization of spark plasma sintered textured(001) MgB_(2)with a record degree of orientation of about 40% and 16% by high-energy ultra-sonication and slip casting in high magnetic field(12 T) and 0 T magnetic field, respectively.Structural characterization was performed by X-ray diffraction, and electron microscopy. The analysis revealed unexpected preferred orientation also in the MgO secondary phase due to the epitaxial growth of(111) MgO on(001) MgB_(2). The influence of oriented microstructure on the superconducting characteristics expressed by critical current density(J_(c)), irreversibility field(H_(irr)), and on the pinning properties were assessed. High anisotropy versus sample orientation in applied magnetic field, H, was observed for J_(c), Hirr, pinning activation energy(U^(*))extracted from relaxation measurements. The zero-field critical current, J_(c0)and F_(p),maxare weakly or not dependent on the direction of H,while the other indicated parameters are significantly influenced. Results enable control of superconducting parameters by further optimization of microstructure through MgB_(2) texturing as a novel and viable strategy for development of bulk MgB2with enhanced properties when taking advantage of its anisotropy.展开更多
基金financial support from MCI-UEFISCDI Romania, the projects PN030101 (21 N/2019), 5PTE/2020 – BIOTEHKER, and POC 37_697 no. 28/01.09.2016 REBMAT。
文摘The paper presents fabrication and characterization of spark plasma sintered textured(001) MgB_(2)with a record degree of orientation of about 40% and 16% by high-energy ultra-sonication and slip casting in high magnetic field(12 T) and 0 T magnetic field, respectively.Structural characterization was performed by X-ray diffraction, and electron microscopy. The analysis revealed unexpected preferred orientation also in the MgO secondary phase due to the epitaxial growth of(111) MgO on(001) MgB_(2). The influence of oriented microstructure on the superconducting characteristics expressed by critical current density(J_(c)), irreversibility field(H_(irr)), and on the pinning properties were assessed. High anisotropy versus sample orientation in applied magnetic field, H, was observed for J_(c), Hirr, pinning activation energy(U^(*))extracted from relaxation measurements. The zero-field critical current, J_(c0)and F_(p),maxare weakly or not dependent on the direction of H,while the other indicated parameters are significantly influenced. Results enable control of superconducting parameters by further optimization of microstructure through MgB_(2) texturing as a novel and viable strategy for development of bulk MgB2with enhanced properties when taking advantage of its anisotropy.
