Ferroic superglasses: Relaxor ferroelectrics PMN and SBN vs. CoFe superspin glass. (3rd October 2018)

• Record Type: Journal Article
• Authors: Kleemann, Wolfgang; Dec, Jan
• Is Part Of: Ferroelectrics. Volume 534(2018)
• Page Start: 1
• Page End: 10
• Publication Date: 2018-10-03
• Subjects: Relaxor ferroelectrics -- random fields -- polar nanoregions -- dynamic criticality -- superdipolar glass -- percolation -- interfacial creep -- segmental relaxation; Ferroelectricity -- Periodicals; Ferroelectric crystals -- Periodicals; 537
• DOI: 10.1080/00150193.2018.1473454
• Languages: English
• ISSNs: 0015-0193

Abstract

Abstract: Random electric fields (RF) due to charge disorder are at the origin of polar nanoregions (PNR) in the cubic relaxor PbMg1/3 Nb2/3 O3 . They initiate Lacroix-Béné-type Cole-Cole semicircles, which achieve Cole-Davidson skew and dynamic power law criticality upon approaching superdipolar glass freezing. Below T g ≈ 240 K percolation of PNR into microdomains is evidenced by interfacial creep and relaxation via Cole-Cole diagrams. Similar behavior occurs in uniaxial Sr0.8 Ba0.2 Nb2 O6 ( T g ≈ 301 K). In contrast, matrix isolated ferromagnetic nanoparticles in CoFe/Al2 O3 multilayers without RF interaction lack all of these effects except superglassy critical dynamics at T g ≈ 46 K.