Clustering and percolation in lithium borate glasses

Vegiri, Alice; Varsamis, Cristos-Platon E.

doi:10.1063/1.1689644

Cited by 25 publications

(18 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the case of silicates, these are predominantly NBOs, while NBOs as well as tetrahedrically coordinated borons (BO 4 ) both contribute in borate glasses. Recent molecular dynamics simulations [36,37] have indicated that the mobility of the alkali ions is significantly higher in the neighborhood of a NBO defect. This may by understood by the broken bond of the NBO that weakens the network locally, while the BO 4 units even strengthen the network in comparison to the trigonal units of the undoped borate network.…”

Section: Ion Conductivity Of Sputter-deposited Oxide Glassesmentioning

confidence: 99%

Nanoanalysis and Ion Conductivity of Thin Film Battery Materials

Schmitz¹,

Abouzari²,

Berkemeier³

et al. 2010

Zeitschrift Für Physikalische Chemie

View full text Add to dashboard Cite

Thin Films / Battery Electrodes / Microscopical Analysis / Glass Membranes / Ionic ConductivityThin film ion-conductive materials may represent essential components of future all-solidstate batteries. Besides, they are also of interest from a fundamental point of view. In this article, the deposition of thin films of complex oxides and amorphous glasses is discussed. Methods of local chemical analysis by analytical electron microscopy and atom probe tomography are described and studies of atomic transport in sputtered network glasses are presented. As experimental examples, thin films of Li borate and silicate glasses, LiCoO 2 , V 2 O 5 , and Li 4 Ti 5 O 12 are addressed.

show abstract

Section: Ion Conductivity Of Sputter-deposited Oxide Glassesmentioning

confidence: 99%

Nanoanalysis and Ion Conductivity of Thin Film Battery Materials

Schmitz¹,

Abouzari²,

Berkemeier³

et al. 2010

Zeitschrift Für Physikalische Chemie

View full text Add to dashboard Cite

show abstract

“…The NBO sites tend to form an assemblage, a so-called cluster, and percolate from one edge to the opposite so as to form a conduction pathway ͑ionic diffusion channel͒. 13 If the population of NBO sites is in the vicinity of the percolation threshold P c ͑24.5% for site percolation of cubic lattice 14 ͒, NBO clusters of various sizes accumulate inside the glass layer. Here, the feature length of the largest cluster is defined as .…”

Section: P14mentioning

confidence: 99%

Thickness Dependence of Proton Conductivity of Amorphous Aluminosilicate Nanofilm

Aoki

Habazaki

Kunitake³

2008

Electrochem. Solid-State Lett.

View full text Add to dashboard Cite

Al x Si 1−x O n films exhibit a drastic change of proton conductivity across the film by reducing their thickness to less than 100 nm. The temperature and humidity dependence of conductivity of the sub-100 nm films is quite different from those of the thicker films. Furthermore, in the former thickness range, the value of conductivity markedly increases with reducing the film thickness, and its thickness dependence follows a power law with a fixed index of −2.1. This size-scaling effect can be explained by the percolation conductivity model that the probability for percolating of the conductive moiety in Al x Si 1−x O n films increases with decreasing the thickness. Proton-and oxide ion-conducting metal oxides have attracted much attention as electrolyte material for solid oxide fuel cells. In particular, nanometer-thick membranes of these oxides are promising for developing next-generation intermediate-temperature fuel cells thanks to diminished area specific resistance ͑ASR͒ enabled by reduction in electrolyte thickness.1-3 Amorphous metal oxides have intrinsic advantages for their application to thin-film electrolyte due to their nongranular covalent networks. Recently, we discovered that silica-based, nanometer-thick films gave high proton conductivity at 100-400°C under nonhumidified atmosphere due to formation of stable Brønsted acid sites when doped with some other metal ions. 4,5 Especially, the aluminosilicate, Al x Si 1−x O n , nanofilm showed the highest proton conductivity and revealed practically usable levels of ASR at around 300°C.5 Several other research groups reported that the ion conductivity of multilayered materials increased with decreasing layer thickness. 6,7 These studies prompted us to study the effect of thickness for our Al x Si 1−x O n film. In fact, it is found that the proton conductivity of amorphous Al x Si 1−x O n films is exponentially enhanced by reduction of thickness into the sub-100 nm regime.The Al x Si 1−x O n film was prepared on an indium-tin-oxide ͑ITO͒ substrate ͑Aldrich͒ by multiple spin-coating of precursor solutions of tetraethoxysilane ͑TEOS͒ ͑Kanto͒ and aluminum sec-butoxide ͓Al͑O s Bu͒ 3 ͔ ͑Kanto͒ at the Al/Si atomic ratio of 5/95. The details of the procedure were described elsewhere. 6 The metal concentration ͑Al + Si͒ in the precursor mixture sol was adjusted in 30 mM for the film of Ͻ100 nm thickness and 100 mM for the film of Ͼ100 nm thickness. A film with thickness of 100 nm was prepared from both of these sols. The precursor sols were spin-coated onto the ITO substrate at 3000 rpm for 40 s by a Mikasa 1H-D7 spin coater. The deposited gel layer was hydrolyzed by blowing hot air for 30 s ͑Iuchi hot gun͒, and the substrate was cooled to room temperature by blowing cold air for 20 s. These cycles of spin-coating, hydrolysis, and cooling were repeated 10-20 times, and the gel film thus obtained was calcined at 400°C for 15 min. The combination of deposition and calcination was repeated more than three times, and the final calcination was performed at 450°C for...

show abstract

“…Clustering processes were also reported in other borate glass systems [19][20][21], but detected with different techniques. It is observed that the concentration where this behaviour is reported depends on the doping ion.…”

Section: Discussionmentioning

confidence: 79%

Double relaxation processes in the glass system xEu2O3·PbO·2B2O3 studied by broadband dielectric spectroscopy

Costa¹

2011

Journal of Non-Crystalline Solids

View full text Add to dashboard Cite

Clustering and percolation in lithium borate glasses

Cited by 25 publications

References 45 publications

Nanoanalysis and Ion Conductivity of Thin Film Battery Materials

Nanoanalysis and Ion Conductivity of Thin Film Battery Materials

Thickness Dependence of Proton Conductivity of Amorphous Aluminosilicate Nanofilm

Double relaxation processes in the glass system xEu2O3·PbO·2B2O3 studied by broadband dielectric spectroscopy

Contact Info

Product

Resources

About