Thermal expansion and Vickers hardness measurements on Bi1.6Pb0.4Sr2Ca2−xSmxCu3Oy superconductors

Yilmazlar, Mustafa; Çetinkara, H.A.; Nursoy, Mustafa; Öztürk, O.; Terzioğlu, C.

doi:10.1016/j.physc.2006.04.093

Cited by 70 publications

(39 citation statements)

References 29 publications

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“…While the further increase of x leads to a change in the reaction rate which retards slightly the (Bi,Pb)-2223 formation. A similar behavior was observed in many previous studies, concerning the effect of R 3+ ions on (Bi,Pb)-2223 phase [11][12][13][14].…”

Section: Characterization and Investigationsupporting

confidence: 90%

“…This result is found to be consistent with the obtained SEM micrograph results. The decrease of the measured Vickers microhardness with increasing of Ho content for x > 0.025 is quite similar to that obtained by [14] in Bi 1.6 Pb 0.4 Sr 2 Ca 2−x Sm x Cu 3 O y phase. They attributed this behavior to the increase of void density and the resistance to crack propagation.…”

Section: Characterization and Investigationsupporting

confidence: 85%

“…The H V -F curve behavior shows that the H V decreases non-linearly as the applied load increases up to 3 N, beyond which the curves tend to attain saturation (nearly plateau) region. This non-linear behavior is also observed for (Bi,Pb)-2223 phase [12][13][14][15][30][31][32][33][34] and it is known as indentation size effect (ISE). The ISE behavior can be explained qualitatively on the basis of penetration depth of the indenter.…”

Section: Characterization and Investigationmentioning

confidence: 89%

“…The previous studies showed that T c values are gradually decreased with the increase of R 3+ content [10][11][12][13][14][15]. The effect of partial substitution of Sm and Eu at Ca site in (Bi,Pb)-2223 system on the superconducting, microstructure, and mechanical properties was studied [12][13][14][15][16]. It was found that the volume fraction of (Bi,Pb)-2223 phase decreases with increasing Sm content.…”

Section: Introductionmentioning

confidence: 97%

“…The effect of chemical substitution/addition on Vickers microhardness for (Bi,Pb)-2223 phase was studied by many groups [12][13][14][15][32][33][34]. It was found that the substitution of Sm at Ca site increases H V due to the enhancement in grain connectivity, and the modified proportional specimen resistance model was found to be the most successful model describing the load independent microhardness [32].…”

Section: Introductionmentioning

confidence: 99%

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Electrical and mechanical properties of (Bi,Pb)-2223 substituted by holmium

et al. 2016

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Abstract:The effect of the partial substitution of Ca 2+ by Ho 3+ ions on the electrical and mechanical properties of the superconducting phase (Bi,Pb)-2223 was studied. Superconducting samples of the type (Bi 1.8 Pb 0.4 )Sr 2 Ca 2.1−x Ho x Cu 3.1 O 10+δ were prepared by solid-state reaction technique under ambient pressure, and characterized by means of X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The superconducting transition temperature T c and pseudogap temperature T * were estimated from electrical resistivity measurements, while the critical current density J c was determined from I-V curves. The electrical resistivity data were discussed according to bipolaron model in the absence of thermally excited individual polarons. The sample with x = 0.025 showed the highest phase volume fraction, T c , and J c . Room temperature Vickers microhardness measurements were carried out at different applied loads (0.25-5 N) in order to investigate the performance of the mechanical properties of (Bi 1.8 Pb 0.4 )Sr 2 Ca 2.1−x Ho x Cu 3.1 O 10+δ phase. It was found that all the samples exhibit normal indentation size effect (ISE). The Vickers microhardness number H V increased as x increased from 0 to 0.025. The experimental results were discussed in view of Meyer's law, Hays-Kendall (HK) approach, elastic/plastic deformation (EPD) model, and proportional specimen resistance (PSR) model. The load independent (true) microhardness of (Bi 1.8 Pb 0.4 )Sr 2 Ca 2.1−x Ho x Cu 3.1 O 10+δ superconducting samples showed identical behavior to that of the PSR model.

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Section: Characterization and Investigationsupporting

confidence: 90%

Section: Characterization and Investigationsupporting

confidence: 85%