Doping controlled metal to insulator transition in the (Bi, Pb)-2212 system

Shabna, R.; Sarun, P.M.; Vinu, S.; Biju, A.; Syamaprasad, U.

doi:10.1088/0953-2048/22/4/045016

Cited by 39 publications

(13 citation statements)

References 16 publications

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“…5). Moreover, no secondary phase containing Cr or any other cation is observed even up to x = 1, indicating that the Cr is incorporated into the crystalline structure of the superconductors produced in this work [26][27][28]. The variation of lattice parameters a and c with Cr content in Bi 1.6 Pb 0.5 Sr 2 Pr x Ca 1.1 Cu 2.1 O y is depicted in Table 1.…”

Section: Xrd Analysesmentioning

confidence: 72%

“…The variation of lattice parameters a and c with Cr content in Bi 1.6 Pb 0.5 Sr 2 Pr x Ca 1.1 Cu 2.1 O y is depicted in Table 1. As seen from the table, the lattice constant, a, increases [29][30][31][32] while the lattice constant, c, decreases with the increase [27,[33][34][35] in the Cr addition. According to these results, the Bi-2212 phase decreases while the Bi-2201 phase starts to increase with the increase of the Cr addition; nevertheless, Fig.…”

Section: Xrd Analysesmentioning

confidence: 84%

See 1 more Smart Citation

Investigation of Structural and Superconducting Properties of Cr Added Bi-2212 Superconducting Ceramics

Yıldırım

Yücel

Bal

et al. 2011

J Supercond Nov Magn

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This study reports the effect of Cr addition on the structural and superconducting properties of Bi 1.8 Sr 2.0 Crx Ca 1.1 Cu 2.1 O y superconductor with x = 0, 0.1, 0.3, 0.5 0.7, and 1 by means of X-ray analysis (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and resistivity measurements. The samples studied in this work were prepared using the standard solid-state reaction method. Zero resistivity transition temperatures (T c ) are qualitatively estimated from the dc resistivity measurements. The zero resistivity transition temperatures are obtained to decrease from 81 K to 53 K with the increase in Cr addition. Moreover, the phase and lattice parameters were determined from XRD measurements. Based on the refinement of cell parameters done by considering the structural modulation, the Cr addition was confirmed by an increase of the lattice parameter a and decrease of the cell parameter a of the samples in comparison with that of the undoped sample (Cr0). As for the microstructure and element composition analyses on the surface of the samples produced, SEM and EDS measurements were investigated. According to the measurements, not only were the grain sizes of the samples noted to decrease, but also the surface morphology and grain connectivity were obtained to degrade with increase in the

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Section: Xrd Analysesmentioning

confidence: 72%

Section: Xrd Analysesmentioning

confidence: 84%

Investigation of Structural and Superconducting Properties of Cr Added Bi-2212 Superconducting Ceramics

Yıldırım

Yücel

Bal

et al. 2011

J Supercond Nov Magn

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“…One can see from the table, the percentage of (Bi, Pb)-2223 phase decreases and that of (Bi, Pb)-2212 phase increases with the Mn addition. Additionally, a systematic expansion in the a-axis length is observed [38][39][40][41] while a regular contraction in the c-axis length is obtained with the increase [42][43][44][45] in the Mn addition. It is well known that the lattice parameter a is controlled by the length of in-plane Cu-O bond [46].…”

Section: Xrd Analysesmentioning

confidence: 80%

“…In our system this bond length is expanded because of the partial replacement of Cu 2+ ions by Mn 4+ ions, leading to an increase in the lattice parameter a, and a decrease in the lattice parameter c. Based on these results, it might be interpreted that the (Bi, Pb)-2223 phase decreases while the (Bi, Pb)-2212 phase starts to increase with the increase of the Mn addition; however, Fig. 3 confirms that the (Bi, Pb)-2223 phase is dominant Moreover, no secondary phase containing Mn or any other cation is observed even up to x = 0.6, presenting the incorporation of Mn atoms into the crystalline structure of the superconductors studied [41][42][43]. Based on these results, the (Bi, Pb)-2223 phase decreases while the (Bi, Pb)-2212 phase starts to enhance with the increase of the Mn addition; however, Fig.…”

Section: Xrd Analysesmentioning

confidence: 84%

Effect of Mn Addition on Structural and Superconducting Properties of (Bi, Pb)-2223 Superconducting Ceramics

Yıldırım

Bal

Yücel

et al. 2011

J Supercond Nov Magn

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This study deals with the effect of Mn addition on the structural and superconducting properties of Bi 1.8 Pb 0.4 Sr 2 Mn x Ca 2.2 Cu 3.0 O y ceramics with x = 0, 0.03, 0.06, 0.15, 0.3 and 0.6 by means of X-ray analysis (XRD), scanning electron microscopy (SEM), electron dispersive X-ray (EDX), resistivity, and transport critical current density (J c ) measurements. Zero-resistivity transition temperatures (T c ) of the samples produced via the standard solidstate reaction method are estimated from the dc resistivity measurements. Moreover, the phase fraction and lattice parameters are determined from XRD measurements while the microstructure, surface morphology and element composition analyses of the samples are investigated by SEM and EDX measurements, respectively. It is found that T c values are obtained to decrease from 109 K to 85 K; likewise, J c values are observed to reduce from 3200 A/cm 2 to 125 A/cm 2 with increasing Mn addition. According to the refinement of cell parameters done by considering the structural modulation, the Mn addition is confirmed by both an increase of the lattice parameter a and a decrease of the cell parameter c of the samples in comparison with that of the pure sample (Mn0). SEM measurements show that not only the surface morphology and grain connectivity are seen to degrade but the grain sizes of the samples are found to decrease with the increase of the Mn addition as well. The EDX results reveal that the elements used for the prepara-

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“…In contrast, if the Meyer number is less than 2, the material exhibits the ISE feature. Additionally, it is well known that Kick's law is valid when the Meyer number is equal to 2, meaning that the hardness is independent upon the applied load [26][27][28][29]. Figure 2 illustrates the plots of lnF versus lnd for all the samples prepared.…”

Section: Analysis According To Meyer's Lawmentioning

confidence: 99%

Experimental and theoretical approaches on mechanical evaluation of Y123 system by Lu addition

Turkoz

Nezir

Öztürk

et al. 2013

J Mater Sci: Mater Electron

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This work is the continuation of a systematic study on the characterization of the Lu-added Y123 bulk superconducting materials prepared by the nitrate compounds and derivatives at 970°C for 20 h. In this part, the effect of Lu inclusions on the physical and mechanical properties of the Y123 superconductors is examined with the aid of microhardness measurements performed at various applied loads in the range of 0.245-2.940 N. The microhardness measurement results allow us to determine the important mechanical characteristics such as Vickers microhardness, elastic (Young's) modulus, yield strength and fracture toughness values being responsible for the potential industrial applications. It is found that all the properties given above are strongly dependent upon the Lu concentration in the Y123 matrix. Especially, Vickers microhardness (H v ) values of the samples studied in this work are found to suppressed considerably with the enhancement of the Lu addition in the system due to the degradation in the connectivity between superconducting grains. Moreover, the H v values of the pure Y123 sample are observed to increase with increasing the applied load whereas those of the Lu-doped superconducting materials are obtained to decrease with the load. In other words, the pure sample exhibits the reverse indentation size effect (RISE) behavior while the others obey the indentation size effect (ISE) feature, confirming the degradation in the mechanical properties with the Lu inclusions in the Y123 matrix. In addition, the microhardness measurement results are estimated using the 5 different models such as Meyer's law, proportional sample resistance model, elastic/plastic deformation model, Hays-Kendall (HK) approach and indentation-induced cracking (IIC) model. According to the results obtained from the simulations, of the mechanical analysis models, the Hays-Kendall (HK) approach is determined as the most successful model for the description of the mechanical properties of the Lu-doped superconducting materials (exhibiting the ISE behavior) where both the both the reversible (elastic) and irreversible (plastic) deformations are produced. On the other hand, the IIC model is found to be superior to other approaches for the pure sample (presenting the RISE feature) where the irreversible deformation becomes more and more dominant compared to the reversible deformation.

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Doping controlled metal to insulator transition in the (Bi, Pb)-2212 system

Cited by 39 publications

References 16 publications

Investigation of Structural and Superconducting Properties of Cr Added Bi-2212 Superconducting Ceramics

Investigation of Structural and Superconducting Properties of Cr Added Bi-2212 Superconducting Ceramics

Effect of Mn Addition on Structural and Superconducting Properties of (Bi, Pb)-2223 Superconducting Ceramics

Experimental and theoretical approaches on mechanical evaluation of Y123 system by Lu addition

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