Pressure-Controlled Synthesis of the Hg0.82Re0.18Ba2Ca2Cu3O8+δ Superconductor

Sin, A.; Cunha, Ana Cristina Barros da; Calleja, A.; Orlando, M. T. D.; Emmerich, Francisco G.; Baggio‐Saitovitch, E.; Segarra, M.; Piñol, S.; Obradors, X.

doi:10.1002/(sici)1521-4095(199810)10:14<1126::aid-adma1127>3.0.co;2-x

Cited by 48 publications

(32 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The filling factor (defined as the ratio between the mass of the sample and the free volume inside the quartz ampoule) which is another important parameter [14], was selected to be around 1 g cm −3 which was high enough for the synthesis temperature used. The precursor film was placed in face contact with the unreacted pellet (5×5×40 mm 3 ) and wrapped together in gold foil.…”

Section: Methodsmentioning

confidence: 99%

Hg-based cuprate superconducting thin films prepared on CeO₂buffered R-plane sapphire substrate

Chromík

Sin²,

Štrbı́k

et al. 2001

Supercond. Sci. Technol.

View full text Add to dashboard Cite

Hg-Ba-Ca-Cu-O films have been grown on CeO 2 /R-plane sapphire substrates using a two-step process. First, a 200 nm thick Ba-Ca-Cu-(O, F) precursor film was prepared by sequential evaporation, then Hg-Re-Ba-Ca-Cu-O pellets as a source of Hg-vapour were applied using heat treatment. The prepared films were continuous with sufficient adhesion to the substrate and a maximum zero-resistance critical temperature of T C0 = 118 K. The x-ray diffraction measurements of all the prepared films confirmed the Hg-1212 phase as well as the minor Hg-1223 phase in some cases. We found that the best results were obtained at the mercuration temperature of 775 • C and an optimal annealing time within the range 0.5-5 h. The superconducting properties of the films prepared under unsuitable conditions were mostly improved after annealing in oxygen atmosphere. Darker parts of the film exhibited a different surface morphology and the presence of the Hg-1223 phase in plate-like grains.

show abstract

Section: Methodsmentioning

confidence: 99%

Hg-based cuprate superconducting thin films prepared on CeO₂buffered R-plane sapphire substrate

Chromík

Sin²,

Štrbı́k

et al. 2001

Supercond. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…It touches the ampoule in the region as b It is possible to increase the maximum pressure as explained in section 2.2. In a previous study it was used a similar sensor for pressures up to 50 bar [12].…”

Section: Tbdta Featuresmentioning

confidence: 99%

“…One of the solutions for heat treatments up to about 900 • C was presented in 1998 by Cunha et al [10,11], which developed an analyzer to measure in-situ gas pressure in the synthesis of ceramic superconductors of high transition-temperature of the family (Hg 1−x ,Re x )Ba 2 Ca 2 Cu 3 O 8+n . Although the previous analyzer was important to find more efficient synthesis routes for the studied superconductors [10][11][12][13][14][15], the uncertainty in the pressure measurement was modest (about ± 0.1 bar) and the data acquisition sampling rate was low (1 reading per minute). In addition, the previous muffle furnace used in the heat treatments was controlled independently from the pressure and temperature sensors, using only 10 power levels.…”

Section: Introductionmentioning

confidence: 99%

An improved analyzer for measuring in-situ gas pressure in sealed quartz tube, and absolute and differential temperatures in heat treatments up to high temperatures

Cunha¹,

Cevolani²,

Cremasco³

et al. 2021

J. Inst.

View full text Add to dashboard Cite

The measurement of in-situ pressure in synthesis and decomposition experiments, carried out in sealed quartz tubes or ampoules, provides important information about the reactions that occur during the heat treatment processes. In this work, a thermobarometric differentialthermal analyzer (TBDTA) is detailed to perform measurements of in-situ pressure in sealed quartz ampoules, and absolute and differential temperatures in heat treatments up to 800 • C. The system can also operate, with certain precautions, above 800 • C to approximately 1100 • C, but in this temperature range the pressure sensor is not so perfectly linear elastic. The uncertainties in the in-situ pressure measurements of the developed analyzer are ± 0.01 bar, and the data acquisition was performed with a sampling rate of 2 readings per second. The analyzer can be used in synthesis and decomposition processes, and in isochoric thermodynamic studies of pure substances. The developed TBDTA was applied to study the vaporization of pure water, and the measurements of pressure and temperature between 200 and 300 • C allowed to determine precise experimental values of the enthalpy of vaporization of the water at 220 • C (the temperature of 220 • C was chosen just as an example). In another application, it was possible to follow, during the heating and vaporization up to about 1000 • C, the in-situ pressure of the element selenium, indicating the formation of different gas species (selenium allotropes in the gaseous phase) as a function of temperature. The results obtained can be considered compatible with mass spectroscopy technique results. K: Calorimeter methods; Electronic detector readout concepts (gas, liquid); Real-time monitoring; Detector control systems (detector and experiment monitoring and slow-control systems, architecture, hardware, algorithms, databases)

show abstract

“…The parameter α in m * = 2 * α * m e represents a factor associated with the effective mass of the conducting superconductor carrier, which comes from the convolution of the CuO 2 molecule symmetry (e.g., octahedral, pyramidal or plane) with the crystal symmetry. Based on the density functional theory (DFT) [14], it is possible to estimate the Fermi velocity (4), which is related to the conductivity tensor (5), n * and m * (6) as follows:…”

Section: Casimir Effect In Hg-12(n − 1)n Superconductorsmentioning

confidence: 99%

“…Our group has investigated Hg 0.8 Re 0.2 Ba 2 Ca 2 Cu 3 O 8+δ in its ceramic form (polycrystalline) since 1998 [5,6]. This compound can be described as three CuO 2 conducting planes separated by layers of essentially insulating material, which is a feature that all high T c cuprates have.…”

Section: Introductionmentioning

confidence: 99%

Pressure effect on Hg-12(n− 1)nsuperconductors and Casimir effect in nanometer scale

Orlando¹,

Belich²,

Alves³

et al. 2008

J. Phys. A: Math. Theor.

View full text Add to dashboard Cite

A description is presented for the Tc pressure-dependent behaviour of Hg-12(n − 1)n superconductors that takes into account the Casimir effect by considering the CuO2 conducting layers to act as plasma sheets. The Casimir energy arises from the parallel plasma sheets (Cu–O planes) whenever these are separated by distances on the nanometer scale. The Tc pressure dependence in Hg-12(n − 1)n superconductors can be described by a pressure-induced charge transfer together with intrinsic terms that are associated with the Casimir energy. For Hg-12(n − 1)n samples with optimum oxygen content, the charge transfer term vanishes, leaving an explicit expression for the intrinsic term. By picking up realistic parameters and inserting them in the expression for the Tc pressure dependence, we have a good agreement with experimental intrinsic term data observed in the mercury family Hg-12(n − 1)n superconductors.

show abstract

Pressure-Controlled Synthesis of the Hg0.82Re0.18Ba2Ca2Cu3O8+δ Superconductor

Abstract: 31.5 eV. Peaks were referenced to carbon at 285.0 eV to account for sample charging. Percentages for each carbon environment quoted within the text are derived from peak areas in the narrow scans.

Cited by 48 publications

References 2 publications

Hg-based cuprate superconducting thin films prepared on CeO₂buffered R-plane sapphire substrate

Hg-based cuprate superconducting thin films prepared on CeO₂buffered R-plane sapphire substrate

An improved analyzer for measuring in-situ gas pressure in sealed quartz tube, and absolute and differential temperatures in heat treatments up to high temperatures

Pressure effect on Hg-12(n− 1)nsuperconductors and Casimir effect in nanometer scale

Contact Info

Product

Resources

About

Pressure-Controlled Synthesis of the Hg0.82Re0.18Ba2Ca2Cu3O8+δ Superconductor

Abstract: 31.5 eV. Peaks were referenced to carbon at 285.0 eV to account for sample charging. Percentages for each carbon environment quoted within the text are derived from peak areas in the narrow scans.

Cited by 48 publications

References 2 publications

Hg-based cuprate superconducting thin films prepared on CeO2buffered R-plane sapphire substrate

Hg-based cuprate superconducting thin films prepared on CeO2buffered R-plane sapphire substrate

An improved analyzer for measuring in-situ gas pressure in sealed quartz tube, and absolute and differential temperatures in heat treatments up to high temperatures

Pressure effect on Hg-12(n− 1)nsuperconductors and Casimir effect in nanometer scale

Contact Info

Product

Resources

About

Hg-based cuprate superconducting thin films prepared on CeO₂buffered R-plane sapphire substrate

Hg-based cuprate superconducting thin films prepared on CeO₂buffered R-plane sapphire substrate