Dynamic Heterogeneity and Ionic Conduction in an Organic Ionic Plastic Crystal and the Role of Vacancies

AbstractA theoretical model of microwave absorption in linear dielectric (non-ferroelectric) ionic crystals that takes into account the presence of point defects was synthesized and verified using NaCl single crystals. In the next stage of this research, we will introduce a controlled density of dislocations into the single crystal NaCl samples and study the effect on the microwave absorption mechanisms (ionic conduction, dielectric relaxation and multi-phonon processes) both theoretically and experimentally. Qualitative outlines of this modified theory are presented. The loss factor ε’ has been measured in the dislocation-free case by a cavity resonator insertion technique and the experimental results are in good agreement with the theoretical model. We describe the sample preparation technique that will be used to produce a controlled dislocation density in single crystal samples that will also be studied in our cavity resonator insertion system.

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Dynamic Heterogeneity and the Role of Non-Native Contacts in the Protein Folding/Unfolding Transitions

Biophysical Journal ◽

10.1016/j.bpj.2015.11.1945 ◽

2016 ◽

Vol 110 (3) ◽

pp. 361a

Author(s):

Toshifumi Mori ◽

Shinji Saito

Keyword(s):

Protein Folding ◽

Dynamic Heterogeneity

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Interfacial Properties of Polymer Nanocomposites: Role of Chain Rigidity and Dynamic Heterogeneity Length Scale

Macromolecules ◽

10.1021/acs.macromol.6b02816 ◽

2017 ◽

Vol 50 (6) ◽

pp. 2397-2406 ◽

Cited By ~ 55

Author(s):

Shiwang Cheng ◽

Bobby Carroll ◽

Wei Lu ◽

Fei Fan ◽

Jan-Michael Y. Carrillo ◽

...

Keyword(s):

Polymer Nanocomposites ◽

Interfacial Properties ◽

Length Scale ◽

Dynamic Heterogeneity ◽

Chain Rigidity

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Assessing the role of static length scales behind glassy dynamics in polydisperse hard disks

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1501911112 ◽

2015 ◽

Vol 112 (22) ◽

pp. 6920-6924 ◽

Cited By ~ 35

Author(s):

John Russo ◽

Hajime Tanaka

Keyword(s):

Correlation Length ◽

Hard Disk ◽

Decay Length ◽

Hard Disks ◽

Dynamic Heterogeneity ◽

Disk System ◽

Slowing Down ◽

Static Correlation ◽

Dynamic Length

The possible role of growing static order in the dynamical slowing down toward the glass transition has recently attracted considerable attention. On the basis of random first-order transition theory, a new method to measure the static correlation length of amorphous order, called “point-to-set” (PTS) length, has been proposed and used to show that the dynamic length grows much faster than the static length. Here, we study the nature of the PTS length, using a polydisperse hard-disk system, which is a model that is known to exhibit a growing hexatic order upon densification. We show that the PTS correlation length is decoupled from the steeper increase of the correlation length of hexatic order and dynamic heterogeneity, while closely mirroring the decay length of two-body density correlations. Our results thus provide a clear example that other forms of order can play an important role in the slowing down of the dynamics, casting a serious doubt on the order-agnostic nature of the PTS length and its relevance to slow dynamics, provided that a polydisperse hard-disk system is a typical glass former.

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Ruthenium Doped Gadolinium Titanate: Effects of a Variable Valent Acceptor on Ionic and Electronic Conduction

MRS Proceedings ◽

10.1557/proc-293-301 ◽

1992 ◽

Vol 293 ◽

Cited By ~ 1

Author(s):

M.A. Spears ◽

H.L. Tuller

Keyword(s):

Electrical Conductivity ◽

Thermoelectric Power ◽

Defect Structure ◽

Oxygen Vacancies ◽

Ionic Conduction ◽

Electronic Conductivity ◽

Electronic Conduction ◽

Defect Band ◽

Electron Migration

AbstractWe have investigated ruthenium doped gadolinium titanate, Gd2(RuxTi1-x)2O7-δ with 0 ≤ x ≤ 0.2, to determine the role of variable valent Ru in influencing the defect structure and transport properties of the pyrochlore host. We have developed a defect chemical model to interpret electrical conductivity, thermoelectric power, and thermogravimetry data. We have found that Ru acts as an acceptor compensated in large part by oxygen vacancies, resulting in enhanced ionic conduction at low values of x. For larger values (x ≈ 0.05), electronic conductivity predominates which we attribute to electron migration by hopping through a Ru-derived defect band.

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Partial electronic and ionic conduction in nanocrystalline ceria: role of space charge

Journal of the European Ceramic Society ◽

10.1016/s0955-2219(03)00525-9 ◽

2004 ◽

Vol 24 (6) ◽

pp. 1919-1923 ◽

Cited By ~ 35

Author(s):

Sangtae Kim ◽

Joachim Maier

Keyword(s):

Space Charge ◽

Ionic Conduction ◽

Nanocrystalline Ceria

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The fate of aluminium in (Na,Bi)TiO3-based ionic conductors

Journal of Materials Chemistry A ◽

10.1039/d0ta03554h ◽

2020 ◽

Vol 8 (35) ◽

pp. 18188-18197

Author(s):

Pedro B. Groszewicz ◽

Leonie Koch ◽

Sebastian Steiner ◽

Azatuhi Ayrikyan ◽

Kyle G. Webber ◽

...

Keyword(s):

Nmr Spectroscopy ◽

Dft Calculations ◽

Ionic Conduction ◽

Impedance Analysis ◽

Ionic Conductors

The role of [AlTi–VO]˙ associated defects in ionic conduction in Al-doped (Na,Bi)TiO3 is clarified by a combination of impedance analysis, DFT calculations and NMR spectroscopy.

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