Aging, rejuvenation and memory due to domain-wall contributions in single crystalsV. Mueller1 and Ya. Shchur2
1 Fachbereich Physik, Martin-Luther-Universität Halle F.-Bach-Platz 6, D-06108 Halle, Germany
2 Institute for Condensed Matter Physics - vul. Sventsits'kogo 1, 79005, L'viv, Ukraine
(Received 5 September 2003; accepted 28 October 2003)
Isothermal aging is studied for crystals which were slowly cooled below the ferroelectric phase-transition temperature . Aging is strong within the temperature range of high dielectric domain-wall contributions, but less pronounced below the domain-freezing temperature . Aging and thermal rejuvenation, setting in if cooling is renewed, are discussed in terms of reconformations of collectively pinned domain walls. Dielectric anomalies, detected upon subsequent reheating in the vicinity of the previous dwelling temperatures, are ascribed to a spatial modulation of the defect structure, carrying memory of the domain-wall roughness established during aging.
77.22.Gm - Dielectric loss and relaxation.
77.80.Dj - Domain structure; hysteresis.
77.84.Fa - KDP- and TGS-type crystals.
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