Glassy Domain Wall Matter in KH2PO4 Crystal: Field-Induced Transition

TL;DR

This study explores how applying a dc electric field induces a transition in the glassy behavior of domain walls in KH2PO4 crystals, revealing distinct phases and a complex T-E phase diagram.

Contribution

It provides the first detailed analysis of field-induced transitions between different glassy phases of domain wall matter in KH2PO4.

Findings

Identification of a field-induced transition from vitreous to glass-ceramic domain wall phases.

Observation of Vogel-Fulcher divergence in timescale { au}f(T, V).

Construction of a T-E phase diagram showing complex glassy patterns.

Abstract

We have investigated the domain wall (DW) dielectric response of potassium dihydrogen phosphate (KH2PO4) crystal under 0-500V dc-bias electric field. Activated DW-contribution onsets freezing at Tf({\omega}, V), some 27K below the ferroelectric TC; timescale {\tau}f(T, V) exhibiting Vogel-Fulcher (VFT) divergence. Sharply distinct low- and high-field behaviors of TC(V), DW-Tg(V), VFT-T0(V), barrier energy Ua(V), and DW glass-fragility m(V) signify a field-induced transition from randomly-pinned/vitreous to clustered/glass-ceramic phases of domain wall matter. Field-hysteresis ({\epsilon}'poled > {\epsilon}'unpoled) observed at high dc-bias indicates coexistent unclustered DW phase, quenched-in during the field-cooling. We construct a paradigm T-E phase diagram depicting the complex glassy patterns of domain wall matter.