Structural and low-field magnetic characterization of superconducting MgB2 wires

Abstract

Superconducting MgB 2 composite wires were prepared by packing blend of MgB 2 inside of Cu tubes using powder in tube (PIT) method. The produced samples of the wires were then characterised by using SEM, XRD and AC susceptibility measurements. The measured fundamental susceptibility is compared with Bean model. We have obtained an empirical functions for the penetration field H p = H a (1Àt) b , where t is the reduced temperature. In addition, ac losses were calculated at the same fixed temperatures to compare theoretical solutions. There is a qualitative agreement between the experimental results and theory.

Low-Field Behavior of Ti-Added<tex>$rm MgB_2/rm Cu$</tex>Superconducting Wires

“…When adding Ti into careful treatment must be done to ensure a good homogeneity of and Ti mixture. In this paper, as an extension of our previously published work [14], we discuss the superconducting properties of copper-clad Ti-added wires for samples annealed at 800 . Measurements of fundamental susceptibility are reported as a function of temperature, ac field amplitude and frequency.…”

The development of MgB2superconducting wires fabricated with an internal Mg diffusion (IMD) process

“…Currently, MgB 2 superconducting wire is primarily fabricated using a powder-in-tube (PIT) process [2][3][4][5][6][7][8][9][10][11][12][13][14][15], in which the raw materials (powders) are packed in a tube, and then the composite is cold-worked (swaged, groove-rolled, and drawn) into a wire. A schematic diagram of the PIT process is shown in the upper part of figure 1.…”

“…A schematic diagram of the PIT process is shown in the upper part of figure 1. Based on the raw materials employed, the PIT process can be divided into two versions: in situ PIT (using a mixture of Mg and B powders) [2][3][4][5][6][7][8][9][10] and ex situ PIT (using MgB 2 powder) [11][12][13][14][15]. In situ PIT has a void problem due to volume shrinkage caused by the reaction between Mg and B, whereas ex situ PIT has low connectivity, because MgB 2 is a hard ceramic.…”

Nonequilibrium Thermodynamics of Ising Magnets

“…It is also called AC or dynamic suceptibility for the magnetization. The dynamic susceptibility is commonly used to determine the electrical properties of superconductors (Kılıç et al, 2004) and magnetic properties of some spin systems such as spin glasses (Körtzler & Eiselt, 1979), cobal-based alloys (Durin et al, 1991), molecule-based magnets (Girtu, 2002), magnetic fluids (Fannin et al, 2005) and nanoparticles (Van Raap et al, 2005). The dynamic magnetic response of these materials and the development of methods for its modification are important for their potential applications.…”