On the Various Approaches to Enhancing the Conductivity of Sodium Sulfate: Review and Current Developments

Gopalan, P.; Saha, Sandeep; Bobade, Santosh M.; Kulkarni, Ajit R.

doi:10.1006/jssc.2000.8916

Cited by 17 publications

(10 citation statements)

References 81 publications

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“…Most sulphate systems such as Li 2 SO 4 , Na 2 SO 4 , Ag 2 SO 4 , and LiNaSO 4 undergo a first-order phase transition from a low temperature, low conductivity phase to a stable high temperature solid electrolyte phase. Although the lithium-based sulphates have the highest conductivity due to the small ionic radius and low atomic weight of Li, they have a solid-solid transformation enthalpy higher than those observed for melting [1]. Na 2 SO 4 and Ag 2 SO 4 behave different: they have reasonably good conductivity, at lower temperatures, and the lower transformation heat.…”

Section: Introductionmentioning

confidence: 91%

“…However, it is impossible to use Ag 2 SO 4 in many applications due to the high cost. Na 2 SO 4 undergoes a first-order phase transition from low temperature orthorhombic phase III to highly conducting high-temperature hexagonal phase I at 241 °C, below that for Li 2 SO 4 [1][2][3][4][5][6]. This transition results in a 4% volume expansion and exhibits a sharp jump by a factor of 10 in conductivity.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Co‐doping effect of Fe₂O₃ on the ionic transport of Na₂SO₄

Torijano¹,

Vargas

Mellander

2007

Phys. Status Solidi (c)

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Thermal and transport properties of Na 2 SO 4 -Fe 2 O 3 composites, with molar composition in the range x = 0.1-0.5, were studied by using impedance spectroscopy and thermal analysis. The electrical conductivity of this solid solution increases rapidly with increasing Fe 2 O 3 content, from a value at about 0.05 × 10 -4 S/cm (for x = 0.0) up to 0.22 × 10 -4 S/cm for x = 0.1. The largest enhancement in the conductivity is observed for 10, 20 and 40 mol% Fe 2 O 3 compositions, a feature not commonly encountered in known composite systems. The step change in the conductivity of pure sodium sulphate at 241 °C, associated with a first order phase transition, that not only shifts slightly to a higher temperatures when the Fe 2 O 3 content increases, but it is also observed a reduction of the step hight. The results are discussed considering an approximation effect of the nanoparticles on the Na+ transport in the Na 2 SO 4 compound.

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Section: Introductionmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Co‐doping effect of Fe₂O₃ on the ionic transport of Na₂SO₄

Torijano¹,

Vargas

Mellander

2007

Phys. Status Solidi (c)

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“…Various approaches to improve the electrical properties of Na 2 SO 4 have recently been reviewed by Gopalan et al [6]. Considering the Frenkel disorder in Na 2 SO 4 , divalent and trivalent dopants have been substituted at Na site resulting in additional vacancies.…”

Section: Introductionmentioning

confidence: 99%

Electrical properties of Na2SO4-based composite systems

Bobade

Kulkarni

Gopalan

2007

Ionics

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Composite electrolytes are well-known multiphase systems and exhibit maxima in the conductivity at certain second-phase concentration. An attempt has been made to investigate a number of sodium sulfate (Na 2 SO 4 )-based composite systems. The dispersoids that have been used are MgO, Al 2 O 3 , and SiO 2 . The samples have been characterized using impedance spectroscopy, X-ray diffraction, and differential scanning calorimetry. The maximum conductivity has been observed for MgO dispersed system, and the percolation threshold has been observed at 30-mol% dispersoid, MgO concentration. Interestingly, two maxima have been observed in case of the Na 2 SO 4 -SiO 2 and Na 2 SO 4 -Al 2 O 3 composite systems. In the Na 2 SO 4 -SiO 2 system, the first maximum occurs at lower concentration, i.e., in the range between 10 and 20 mol%, whereas the second occurs at the 40-mol% dispersoid concentration. For the Na 2 SO 4 -Al 2 O 3 system, although slightly indistinguishable, two peaks in the conductivity vs composition plot have been observed around 12-and 30-mol% Al 2 O 3 concentrations.

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“…The high temperature phase is of interest particularly because of its high electrical conductivity. Various groups have explored the electrical properties and structural behavior of Na 2 SO 4 Various approaches have been employed to improve the electrical conductivity of Na 2 SO 4 [20][21][22]. Composite formation is one of the approaches to improve the conductivity of host.…”

Section: Introductionmentioning

confidence: 99%