Microstrutural Features of Magnetic NiCoB Nanoparticles Addition to MgB2 Precursor Powders

Scientific paper - Original scientific paper

• Author: Ivana Lončarek; MBZ: 291090
• Author: Anđelka Tonejc; MBZ: 50121
• Author: Željko Skoko; MBZ: 236445
• Author: Nikolina Novosel; MBZ: 291016
• Author: Mislav Mustapić; MBZ: 352130
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

Magnesium diboride (MgB2) is a superconductor characterized by interesting properties like rather high superconducting transition temperature Tc = 39 K, long coherence length and low anisotropy. In addition, it has a very simple crystal structure and low density. Those properties make the MgB2 an ideal candidate for a wide range of applications. To improve the electromagnetic properties of MgB2, magnetic nickel-cobalt-boron (NiCoB) nanoparticles (mean grain size 17 ± 3 nm) were added to Mg and B precursor powders and sintered at 650 °C, i.e. the temperature of MgB2 superconductor formation. The nearly spherical NiCoB nanoparticles, as-prepared by the chemical reduction of metallic salts, were amorphous according to previous study. The resulting MgB2 sample, formed after the sintering at 650 °C, was subjected to detailed microstructural analysis which included the application of various experimental methods: XRD, FE-SEM, EDS, elemental mapping, TEM and SAED. The methods confirmed the formation of new crystal CoNi phase (due to heat treatment at 650C), consisting of spherical nanoparticles (~ 6 nm) with tendency to spherical agglomerates formation. Those nanosized magnetic particles (characterized by the single domain magnetic structure and blocking temperature TB below room temperature), located at MgB2 grain boundaries, could serve as effective magnetic pinning centers in MgB2, thus improving its electromagnetic properties

• Keywords (english): magnetic diboride; CoNi nanoparticles; Rietveld refinement; SEM; TEM
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Croatica Chemica Acta
• Numbering: vol. 90, no. 1, pp. 37-51
• p-ISSN: 0011-1643
• e-ISSN: 1334-417X
• DOI: https://doi.org/10.5562/cca2985
• URN:NBN: urn:nbn:hr:217:103277
• Publication: 2017
• Project: Number: 119-0982886-1009; Title (croatian): Struktura i svojstva posebnih nanomaterijala dobivenih suvremenim tehnikama; Leader: Antun Tonejc; Jurisdiction: Croatia; Funding stream: ZP
• Document URL: http://hrcak.srce.hr/182670
• Type of resource: Text
• Access conditions: Open access
• Public note: This work is licensed under a Creative Commons Attribution 4.0 International License. Received: August 31, 2016. Revised: March 7, 2017. Accepted: March 13, 2017. Published online: June 8, 2017.
• Created on: 2020-02-28 21:01:33