Scaling parallels in the non-Debye dielectric relaxation of ionic glasses and dipolar supercooled liquids

Journal Article · Tue Jul 01 04:00:00 EDT 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.56.170· OSTI ID:531806

Sidebottom, D L; Green, P F; Brow, R K ^[1]

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1. Sandia National Laboratories, Albuquerque, New Mexico 87185-1349 (United States)

We compare the dielectric response of ionic glasses and dipolar liquids near the glass transition. Our work is divided into two parts. In the first section we examine ionic glasses and the two prominent approaches to analyzing the dielectric response. The conductivity of ion-conducting glasses displays a power law dispersion {sigma}({omega}){proportional_to}{omega}{sup n}, where n{approx}0.67, but frequently the dielectric response is analyzed using the electrical modulus M{sup {asterisk}}({omega})=1/{var_epsilon}{sup {asterisk}}({omega}), where {var_epsilon}{sup {asterisk}}({omega})={var_epsilon}({omega}){minus}i{sigma}({omega})/{omega} is the complex permittivity. We reexamine two specific examples where the shape of M{sup {asterisk}}({omega}) changes in response to changes in (a) temperature and (b) ion concentration, to suggest fundamental changes in ion dynamics are occurring. We show, however, that these changes in the shape of M{sup {asterisk}}({omega}) occur in the absence of changes in the scaling properties of {sigma}({omega}), for which n remains constant. In the second part, we examine the dielectric relaxation found in dipolar liquids, for which {var_epsilon}{sup {asterisk}}({omega}) likewise exhibits changes in shape on approach to the glass transition. Guided by similarities of M{sup {asterisk}}({omega}) in ionic glasses and {var_epsilon}{sup {asterisk}}({omega}) in dipolar liquids, we demonstrate that a recent scaling approach proposed by Dixon and co-workers for {var_epsilon}{sup {asterisk}}({omega}) of dipolar relaxation also appears valid for M{sup {asterisk}}({omega}) in the ionic case. While this suggests that the Dixon scaling approach is more universal than previously recognized, we demonstrate how the dielectric response can be scaled in a linear manner using an alternative data representation. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 531806
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 1 Vol. 56; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMORPHOUS STATE
COOLING
CRYSTAL-PHASE TRANSFORMATIONS
DIELECTRIC PROPERTIES
DYNAMICS
GLASS
IONIC CONDUCTIVITY
IONIC CRYSTALS
PERMITTIVITY
RELAXATION