Electrical and mechanical properties of Mn₂O₃ nanoparticles / SmBa₂Cu₃O_7-δ composite

ABSTRACT

(Mn₂O₃)_x SmBa₂Cu₃O_7-δ composite samples (0.00 ≤ x ≤ 0.08 wt.%) were prepared using solid state reaction technique, and investigated using resistivity measurements and the Vickers microhardness. The characterisation of the prepared samples was accomplished using X-ray powder diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), and Brunauer-Emmett-Teller (BET). The Mn₂O₃ nanoparticles do not influence the orthorhombic structure of SmBa₂Cu₃O_{7- δ} and stay as adhering material producing a filling up of the voids and reducing the cracks. BET measurements show a decrease in the specific surface area as well as in the total pore volume for x = 0.02 wt.%, confirming the SEM results. The superconducting transition temperature T_c of the prepared samples was investigated using electrical resistivity measurements. Results showed that T_c increases from 91.68 K to 94.43 K as x increases from 0.00 to 0.02 wt.%, then it decreases as nano-Mn₂O₃ wt.% concentration increases. The mechanical properties of (Mn₂O₃)_xSmBa₂Cu₃O_7-δ samples were measured using Vickers microhardness in order to investigate the effect of Mn₂O₃ nanoparticles on Vickers microhardness number H_v. The Vickers microhardness data were analysed using Meyer’s law, Hays and Kendall (HK), and Modified Proportional Specimen Resistance (MPSR) models. The analysis showed that the HK is the best model to describe the load dependence of H_v for all samples.

KEYWORDS:

• Superconductor SmBa₂Cu₃O_7-δ
• Mn₂O₃ nanoparticles
• X-ray diffraction
• Vickers microhardness

Disclosure statement

No potential conflict of interest was reported by the authors.