Superconductivity of nano-TiO2-added MgB2

Kishan, H.; Awana, V. P. S.; Oliveira, Tamires Morete de; Alam, Sher; Saito, Mitsuhiro; Lima, Orlando Fontes

doi:10.1016/j.physc.2007.02.014

Cited by 10 publications

(3 citation statements)

References 16 publications

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“…For this sample set the best results (10 5 A cm −2 and 10 4 A cm −2 at 6 T and 11.5 T, respectively) are found when the excess-Mg level is raised to 15% and SiC is added. Still further improvements are depicted in figure 7 which emphasizes the effectiveness of [49] Nanodiamond [57][58][59] HoO 2 [70] Zr [77] Malic acid [87] ZrB 2 [5,44] TiC [60,61] A l 2 O 3 [71] Mo [78] Maleic anhydride [41] TiB 2 [5] S i C [ 38,42,[62][63][64][65] MgO [45] F e [ 79] Paraffin [88] NbB 2 [5] B 4 C [40, 66, 67] T i O 2 [72] C o [ 80] Toluene [89] Na 2 CO 3 [68] P r 6 O 11 [73] Ni [80] Ethanol [89] CaB 6 [50] S i O 2 [74] C u [ 81] Acetone [89] WSi 2 [51][52][53] A g [ 82] Tartaric acid [90] ZrSi 2 [51,52] A l [ 83] Ethyltoluene [91] Si [84] La [85] the C-containing dopants e.g. maleic anhydride, SiC, and C itself when appropriately introduced.…”

Section: Critical Current Density and Its Enhancement By Doping And F...mentioning

confidence: 99%

Prospects for improving the intrinsic and extrinsic properties of magnesium diboride superconducting strands

Collings

Sumption

Bhatia

et al. 2008

Supercond. Sci. Technol.

166

134

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The magnetic and transport properties of MgB 2 films represent performance goals yet to be attained by powder-processed bulk samples and conductors. Carbon-doped films have exhibited upper critical fields, μ 0 H c2 , as high as 60 T and a possible upper limit of more than twice this value has been predicted. Very high critical current densities, J c , have also been measured in films, e.g. 25 MA/cm 2 in self field and 7 kA/cm 2 in 15 T. Such performance limits are still out of the reach of even the best MgB 2 magnet wire. In discussing the present status and prospects for improving the performance of powder-based wire we focus attention on (1) the intrinsic (intragrain) superconducting properties of MgB 2 --H c2 and flux pinning, (2) factors that control the efficiency with which current is transported from grain-to-grain in the conductor, an extrinsic (intergrain) property. With regard to Item-(1), the role of dopants in H c2 enhancement is discussed and examples presented. On the other hand their roles in increasing J c , both via H c2 enhancement as well as direct fluxoid/pining-center interaction, are discussed and a comprehensive survey of H c2 dopants and flux-pinning additives is presented. Dopant selection, chemistry, methods of introduction (inclusion), and homogeneity of distribution (via the rounding of the superconducting electronic specific heat transition) are considered. Current transport through the powder-processed wire (an extrinsic property) is partially blocked by the inherent granularity of the material itself and the chemical or other properties of the intergrain surfaces. Overall porosity, including reduced density and intergranular blocking, is quantified in terms of the measured temperature dependence of the normal-state resistivity compared to that of a clean single crystal. Several experimental results are presented in terms of percent effective cross-sectional area for current transport. These and other such results indicate that in many cases less than 15% of the conductor's cross sectional area is able to carry transport current. It is pointed out that densification in association with the elimination of grain-boundary blocking phases would yield five-to ten-fold increases in J c in relevant regimes, enabling the performance of MgB 2 in selected applications to compete with that of Nb 3 Sn. imaging. But to take the next step, whether we are interested in high field 4 K operation, or in the more energy efficient 20 K temperatures regimes well out of the range of the present NbTi and Nb 3 Sn wires, further improvement of the in-field J c is needed. In addressing this issue we must recognize two classes of properties (what might be termed "intrinsic" and "extrinsic", respectively) that are in urgent need of fundamental research. Below, we summarize some of the key issues that need to be addressed. Keywords Intrinsic PropertiesThe essential intrinsic (i.e.intragranular) properties of polycrystalline MgB 2 are H c2 and flux pinning (or, alternatively, intra-grain J c Necessary ...

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Section: Critical Current Density and Its Enhancement By Doping And F...mentioning

confidence: 99%

Prospects for improving the intrinsic and extrinsic properties of magnesium diboride superconducting strands

Collings

Sumption

Bhatia

et al. 2008

Supercond. Sci. Technol.

166

134

View full text Add to dashboard Cite

show abstract

“…Thus through EDS results, the actual percentage ratio cannot be determined as very light elements boron and carbon are lesser sensitive in comparison to others elements [15]. In nano-TiO 2 doped samples [51] almost similar micrographs for all samples was found irrespective of whether they are doped with n-TiO 2 or not. In their study with HRTEM it was concluded that several black holes that appear in the image are presumably the n-TiO 2 .…”

Section: Limitationsmentioning

confidence: 94%

Exploring the Superconductors with Scanning Electron Microscopy (SEM)

Singh¹,

Sharma²,

Husain³

et al. 2012

Scanning Electron Microscopy

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“…Recently, TiO 2 has demonstrated its potential as a highly effective candidate for reinforcing superconductor ceramics. Therefore, several studies were conducted using TiO 2 as an additive to some of the superconducting compounds, such as MgB 2 [12][13][14], BPSCCO [15], Bi-2212, and Bi-2223 [16]. The effect of TiO 2 addition on the YBCO bulk has been reported a few times using a variety of synthesis methods.…”

Section: Introductionmentioning

confidence: 99%

Orthorhombic YBa2Cu3O7−δ Superconductor with TiO2 Nanoparticle Addition: Crystal Structure, Electric Resistivity, and AC Susceptibility

Barood,

Kechik,

Tee

et al. 2023

Coatings

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This article reports the effect of a nanoscale addition of TiO2 on the structure and superconducting parameters of the high-temperature superconductor YBa2Cu3O7-δ (Y123). Polycrystalline compounds of Y123 with different percentages of TiO2, x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0, were fabricated using the thermal treatment method. An analysis using X-ray diffraction confirmed the formation of Y123 phases for all composite samples. Field-emission scanning electron microscopy (FESEM) analysis revealed the growth of grain size and decrease in porosity, with a sign of partial melting of grains for the samples with TiO2 addition. The magnetic and electric transport properties were investigated using AC susceptibility measurement and the four-probe method, respectively. It was observed that the superconducting transition temperature, Tc-onset, for a pure sample determined by ACS and 4PP was 95.6 K and 95.4 K, respectively. These values were found to decrease with the addition of TiO2, while the superconducting transition (∆Tc) improved with TiO2 addition except for the sample at x = 0.2 wt.%, which showed the broadest transition width. The sharpest superconducting transition (∆Tc) was observed for the sample at x = 1.0 wt.%, indicating that the addition of TiO2 nanoparticles is expected to serve as artificial pinning centres and strengthen the connection among the grains in the Y123 ceramic.

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Superconductivity of nano-TiO2-added MgB2

Cited by 10 publications

References 16 publications

Prospects for improving the intrinsic and extrinsic properties of magnesium diboride superconducting strands

Prospects for improving the intrinsic and extrinsic properties of magnesium diboride superconducting strands

Exploring the Superconductors with Scanning Electron Microscopy (SEM)

Orthorhombic YBa2Cu3O7−δ Superconductor with TiO2 Nanoparticle Addition: Crystal Structure, Electric Resistivity, and AC Susceptibility

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