Absence of critical exponents in ferroelectrics: experiments of Hilczer and theory of Levanyuk and Sigov. (2nd August 2016)

• Record Type: Journal Article
• Authors: Scott, J.F.
• Is Part Of: Phase transitions. Volume 89:Number 7/8(2016)
• Page Start: 645
• Page End: 650
• Publication Date: 2016-08-02
• Subjects: critical exponents -- experiments -- ferroelectrics -- theory; Phase transformations (Statistical physics) -- Periodicals; 530.47405
• DOI: 10.1080/01411594.2015.1127923
• Languages: English
• ISSNs: 0141-1594

Abstract

Abstract : The pioneering breakthrough of Bozena Hilczer and her coworkers showed that the so-called critical phenomena in many ferroelectric crystals are entirely produced by defects. She studied gadolinium aluminum sulphate hexahydrate (GASH), lithium ammonium sulphate, lithium hydrazinium sulphate, PZT, barium titanate, and especially TGS, via neutron irradiation, X-ray irradiation, and e-beam electron irradiation, which showed that the divergences in specific heat or dielectric constant near the Curie temperature T c are not caused by 'critical' fluctuations but by static defects, which can be annealed out and subsequently reproduced by irradiation. This work is rarely cited (modern physicists often feel that literature searches are optional), leading to frequent rediscovery and generally spurious claims of true 'critical' phenomena near T c .