Tackling the agglomeration of Mg2Si dopant in MgB2 superconductor using cast Mg–Si alloy. (September 2017)

• Record Type: Journal Article
• Authors: S., Rahul; Thomas, Syju; K.M., Devadas; Varghese, Neson; Paulose, Ajeesh P.; Varma, Manoj Raama; U., Syamaprasad
• Is Part Of: Materials research bulletin. Volume 93(2017)
• Page Start: 296
• Page End: 302
• Publication Date: 2017-09
• Subjects: A. Superconductors -- B. Microstructure -- C. X-ray diffraction -- C. Transmission electron microscopy (TEM) -- D. Superconductivity; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2017.05.022
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: Highlights: Casting technique is employed to prepare Mg-Si alloy with uniformly distributed Mg2 Si particles, reducing agglomeration. Mg2 Si along with added nano carbon cause systematic variations in the structural and superconducting properties of MgB2 . Improvement in JC for the sample prepared from Mg-Si cast alloy is better than that in the sample prepared by normal route. Uniform distribution of pinning centres in the samples made from cast alloy is the reason for their improved performance. Abstract: The work demonstrates a method to tackle the agglomeration of Mg2 Si dopant in chemical doping in MgB2 superconductor to enhance its in-field critical current density. Mg-Si alloy which has uniformly distributed Mg2 Si particles in it is prepared by casting technique. The alloy is used as the Mg source for the preparation of MgB2 samples doped with various weight percentage of nano carbon. XRD patterns show peaks of Mg2 Si in all Si containing samples. SEM images show a microstructure with distinctly smaller grains and reduced crystallinity in doped samples. HRTEM analysis confirms that the method led to better distribution of Mg2 Si particles within the MgB2 grains as compared to the normally prepared sample. It is found that doping has not severely affected the transition temperature of the samples and at the same time enhanced the in-field critical current density.