The effect of nano-diamond additives on the enhancement of critical current density and related performance of bulk MgB2

: Vajpayee A, Huhtinen H, Awana VPS, Gupta A, Rawat R, Lalla NP, Kishan H, Laiho R, Felner I, Narlikar AV

Publisher: IOP PUBLISHING LTD

: 2007

: Superconductor Science and Technology

: SUPERCONDUCTOR SCIENCE & TECHNOLOGY

: SUPERCOND SCI TECH

: 20

: 9

: S155

: S158

: 4

: 0953-2048

DOI: https://doi.org/10.1088/0953-2048/20/9/S07

We report the synthesis, high-resolution micro-structure, magneto-transport and magnetization of nano-diamond doped MgB2-nD(x) with x =0.0-0.1. The superconducting transition temperature (T-c) is not affected by x up to x = 0.05, indicating that the added nano-diamond ( 1) does not decompose to C and (2) does not partially substitute for B in MgB2. R(T) versus H measurements show higher Tc values under the same applied magnetic field for the nano-diamond added samples, resulting in higher estimated H-c2 values. Isothermal magnetization measurements show that above 2 T, the critical current density (j(c)) is of the order of 105 A cm(-2) for the pristine sample. jc is further increased to three times for 3% nano-diamond doped samples. High-resolution transmission electron microscopy (HRTEM) observations clearly show the dispersion of nano-diamond particles, with an average particle size of 8-10 nm, in the MgB2 matrix. It seems likely that the dispersed nano-diamond particles of below 10 nm in size are acting as effective pinning centres responsible for improving the superconducting performance of the parent MgB2.