Improvements in the Dispersion of Nanosilver in a MgB₂ Matrix through a Graphene Oxide Net

Abstract

The effects of graphene oxide (GO) addition on the dispersion of nanosilver (Ag) in an MgB2 matrix were studied using bulk samples prepared through a diffusion process. The influence of the dispersion of Ag and Ag/GO particles on the critical current density ( Jc) of MgB2 was also investigated. GO has emerged as an excellent dopant which can significantly improve both the low-and high-field performance of MgB2 due to its capability to improve intergrain connectivity (GO) and inter-and intragrain pinning (GO and AgMg). The addition of nanosize Ag particles also results in an improvement of vortex pinning, and at the same time, it offers the advantage of preventing the loss of Mg during the sintering process. It is found that the dispersion of nanosilver in the presence of GO results in significant improvements in the critical current density in MgB2, particularly at high magnetic fields, due to improved intergrain connectivity and flux pinning. The use of the GO net as a platform for doping MgB2 in our case with Ag yielded a 10-fold-better critical current density ( Jc) than standard Ag doping at 9 T and 5 K. Even without sophisticated processes, we obtained a Jc result of 10 4 A/cm 2 at 9 T and 5 K, which is one of the best ever achieved. Corresponding author: mislav@uow.edu.au ABSTRACT:The effects of graphene oxide (GO) addition on the dispersion of nano-silver (Ag) in an MgB 2 matrix were studied using bulk samples prepared through a diffusion process. The influence of the dispersion of Ag and Ag/GO particles on the critical current density (J C ) of MgB 2 was also investigated. GO has emerged as an excellent dopant which can significantly improve both low-and high-field performance of MgB 2 due to its capability to improve inter-grain connectivity (GO), and inter-and intra-grain pinning (GO and AgMg). The addition of nano-size Ag particles also results in improvement of vortex pinning, and at the same time, it offers the advantage of preventing the loss of Mg during the sintering process. It is found that dispersion of nano-silver in the presence of GO results in significant improvements to the critical current density in MgB 2 , particularly at high magnetic fields, due to improved inter-grain connectivity and flux pinning. The use of the GO net as a platform for doping MgB 2 in our case with Ag, yielded a 10 times better critical current density (J C ) than standard Ag doping at 9 T and 5 K. Even without sophisticated processes, we obtained J C result of 10 4 A/cm 2 at 9 T and 5 K, which is one of the best ever achieved.

Homogeneity of SiC distribution in IMD MgB2 wires

“…Residual agglomerates of dopants in the mixed powders will still exist in the final products. Plenty of previous works have been carried out to overcome the uniform distribution of dopants in the matrix [22][23][24][25][26]. Among them, ball milling is an effective and widely used method [27][28][29].…”

Processable 2D materials beyond graphene: MoS2liquid crystals and fibres

“…Such a development has indeed occurred for graphene oxide (GO) with the formation of liquid crystalline (LC) disper-sions of GO [15][16][17] that have allowed the fabrication of graphenebased devices using wet-spinning, 8,9,[18][19][20] printing and coating, 21 for a broad range of applications in energy storage, 9,[22][23][24] superconductors, 25,26 optoelectronics 27,28 and structural materials. 15,29 In an analogous fashion, LC 2D TMDs could serve as a platform for the rational design and fabrication of TMD-based materials for harnessing and translating their useful properties into practical device applications.…”