Affiliation:
1. Department of Physics, Faculty of Science, Alexandria University 1 , Baghdad St., Moharrem Bey, Alexandria21544, Egypt
2. Oman Hydrogen Centre, German University of Technology in Oman (GUtech) 2 , Muscat Express Hwy., Halban122, Sultanate of Oman (Corresponding author), e-mail: hadi.basma@gutech.edu.om , ORCID link for author moved to before name tags https://orcid.org/0000-0002-0060-5259
3. Department of Physics, Faculty of Science, Beirut Arab University 3 , Riad Al Solh, Beirut1107, Lebanon
Abstract
Abstract
The current study reports the synthesis of nano-(CdO)x/Bi1.6Pb0.4Sr1.9Ca1.1Cu2.1Oy, nano-(Cd0.95Mn0.05O)x/Bi1.6Pb0.4Sr1.9Ca1.1Cu2.1Oy, and nano-(Cd0.95Fe0.05O)x/Bi1.6Pb0.4Sr1.9Ca1.1Cu2.1Oy composites, with x = 0.00, 0.01, 0.02, 0.05, and 0.10 wt. %, respectively, using the classical solid-state reaction technique. X-ray powder diffraction (XRD) confirmed the formation of an orthorhombic structure of the (Bi, Pb)-2212 as the major phase. Thermogravimetric analysis was utilized to evaluate the thermal stability of the pure sample throughout the different stages of phase formation and the effect of nanoparticle addition. The weight loss/gain from the three additions is related to the excess of oxygen, as confirmed via iodometric titration analysis and from the findings of oxygen diffusion energy. Room temperature Vickers microhardness (HV) measurements were conducted at various applied loads (0.49–9.8 N). Based on the Vickers microhardness (HV) measurements, the optimum addition of nanoparticles for increasing the microhardness of the (Bi, Pb)-2212 phase was at x = 0.05 wt. % for all superconducting composites. Iron doped Cadmium Oxide (CdFeO) nanoparticles have the greatest enhancement on the Vicker hardness values (HV) at the plateau region. Furthermore, various mechanical parameters for potential applications, such as elastic modulus (E), yield strength (Y), and fracture toughness (K) of the samples under study, were consequently extracted from HV as a function of nanoparticle addition. Moreover, CdFeO addition outperformed CdO and Manganese doped Cadmium Oxide (CdMnO) addition in improving the parameters of E, Y, K, and B, which display better ductility and an enhanced capacity to resist indentation fractures and facilitate (Bi-2212) manufactured in the form of round wires that can be used in high magnetic field magnets, nuclear magnetic resonance instruments, and large hadron colliders. Different models were theoretically used to analyze the measured HV data in the plateau limit regions. The indentation-induced cracking model offered the most accurate theoretical model at the plateau limit region based on Vickers microhardness (HV) observations.