The distribution of relaxation times in dielectrics

Garton, Charles

doi:10.1039/tf946420a056

Cited by 44 publications

(11 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The existence of NCL in glassy ionic conductors is well known. Evidences for its existence was suggested repeatedly over the span of several decades [1][2][3][4][5][6][7][8][9][10][11][12] and it is now considered to be a universal characteristic of ionic conductors, 13,14 although till now there are only a few investigations of its properties. [11][12][13][14][15][16][17][18][19] This NCL contribution appears at higher frequency than the ion hopping ac conductivity hop Ј ( ).…”

Section: ͑2͒mentioning

confidence: 99%

Cage decay, near constant loss, and crossover to cooperative ion motion in ionic conductors: Insight from experimental data

2002

View full text Add to dashboard Cite

Experimental frequency-dependent conductivity relaxation spectra of a number of molten, glassy, and crystalline ionic conductors that show both the presence of the near constant loss ͑NCL͒ and the cooperative ion hopping contribution are analyzed. On decreasing frequency, the NCL appears first but terminates at some frequency x1 . At still a lower frequency x2 the cooperative ion hopping dispersion takes over. The independent ion hopping frequency 0 of the coupling model is calculated from the parameters characterizing the cooperative ion hopping dispersion. It is found for all ionic conductors that x1 ӷ 0 , and 0 always fall inside the frequency region x1 Ͼ Ͼ x2 . The empirical results leads to a qualitative theory for the origin of the NCL, which gives physical meanings of the two crossover frequencies x1 and x2 , as well as explaining the role of the independent hopping frequency 0 , in determining them. The weak temperature dependence of the NCL has been recaptured by the qualitative theory. An improved understanding is gained of the evolution of the ion dynamics from early times when the cages decay very slowly with time, giving rise to the near constant loss, to long times when ions move cooperatively, leading finally to dc conductivity.

show abstract

Section: ͑2͒mentioning

confidence: 99%

Cage decay, near constant loss, and crossover to cooperative ion motion in ionic conductors: Insight from experimental data

2002

View full text Add to dashboard Cite

show abstract

“…(2). The existence of a nearly constant loss (NCL) was suggested repeatedly over the span of several decades [23], and it is now considered to be a universal characteristic of ionic conductors [24], although till now there have been only a few investigations of its properties [24][25][26][27]. Measurements at low temperatures and high frequencies where the ac conductivity data are dominated by the NCL contribution are scarce.…”

mentioning

confidence: 99%

Cation Mass Dependence of the Nearly Constant Dielectric Loss in Alkali Triborate Glasses

et al. 2002

View full text Add to dashboard Cite

Electrical ac conductivity measurements on alkali triborate glasses ( M2O x 3B2O3, M = Li, Na, K, and Rb) were performed at temperatures down to 8 K and frequencies up to 1 GHz. All samples show a nearly constant dielectric loss (NCL), at the limit of high frequencies and/or low temperatures. The magnitude of the NCL is found to decrease as m(-1/3) with increasing alkali ion mass m. This quantitative result for the NCL, closely related to the mean-square displacement of ions, indicates that the origin of the NCL might be related to vibrational relaxation of the ions in the anharmonic potentials that cage them, and the cage is decaying very slowly with time.

show abstract

“…The existence of the NCL was suggested repeatedly over the span of several decades [8][9][10][11][12][13][14][15][16][17][18][19][20], and it is now accepted to be a universal characteristic of ionic conductors although its origin is still not totally clear. From analyses of experimental [20] and molecular dynamics simulation data [33], the NCL occurs in the short time regime when the ions are still caged and before they can diffuse to neighboring sites, indicating that NCL is a determining factor in ion diffusion.…”

Section: Nature Of the Dynamics Responsible For The Nclmentioning

confidence: 99%

“…At sufficiently high frequency or low temperature, the dynamic response of glassy, crystalline and molten ionic conductors changes to e 00 (x) = (A/e 0 )x Àa or r 0 (x) = Ax 1 À a , where e 00 (=r 0 /xe 0 ) is the imaginary part of the complex permittivity, e 0 is the permittivity of vacuum, a is a small positive number, and A is a constant with a weak temperature dependence [8][9][10][11][12][13][14][15][16][17][18][19][20]. Since e 00 (x) varies very slowly with frequency, it is called the nearly constant loss (NCL).…”

Section: Introductionmentioning

confidence: 99%

Molecular dynamics simulations of the dynamics of ions in single and mixed alkali glasses

Habasaki

Ngai

Hiwatari

et al. 2004

Journal of Non-Crystalline Solids

View full text Add to dashboard Cite

The distribution of relaxation times in dielectrics

Cited by 44 publications

References 0 publications

Cage decay, near constant loss, and crossover to cooperative ion motion in ionic conductors: Insight from experimental data

Cage decay, near constant loss, and crossover to cooperative ion motion in ionic conductors: Insight from experimental data

Cation Mass Dependence of the Nearly Constant Dielectric Loss in Alkali Triborate Glasses

Molecular dynamics simulations of the dynamics of ions in single and mixed alkali glasses

Contact Info

Product

Resources

About