The barkhausen effect

Switching current noise and relaxation of ferroelectric domains

“…The electrical Barkhausen noise has been observed experimentally in BaTiO 3 [1,2,7] and Gd 2 (MoO 4 ) 3 and LiTaO 3 [8,9] single crystals and in 9.4/65/35(Pb, La)(Zr, Ti)O 3 (PLZT) ceramics [10] and PbMg 1/3 Nb 2/3 O 3 (PMN) relaxor ferroelectric [11]. Physically, the polarization reversal and domain wall motions in ferroelectrics is accompanied with the local change of sign of bound charges, which influences values of the electric field in the sample.…”

“…In particular, it is a key process that takes place in electronic devices based on ferroelectrics thin films, where a reproducible switching process is required. Apart from the extensive experimental and theoretical work [1][2][3], a complete understanding of the domain-wall motion and predictability of the switching processes remains elusive in real ferroelectrics, especially when several physical parameters, determining either structure or dynamics, are varied. Domain switching and relaxation (back-switching) in ferroelectrics can be studied by hysteresis loop, switching current, and switching current bursts (electrical Barkhausen noise).…”

“…We simulate field-induced nucleation and switching of domains in a three-dimensional model of ferroelectrics with quenched disorder and varying domain sizes. We study (1) bursts of the switching current at slow driving along the hysteresis loop (electrical Barkhausen noise) and (2) the polarization reversal when a strong electric field was applied and back-switching after the field was removed. We show how these processes are related to the underlying structure of domain walls, which in turn is controlled by the pinning at quenched local electric fields.…”

Single Domain State Stability in TGS Single Crystals

“…Polarization reversal in ferroelectrics is usually accompanied by jump-like processes of domain structure realignment (Barkhausen effect). Direct observation of domain kinetics in triglycine sulphate (TGS) using nematic liquid crystals has shown that Barkhausen pulses are associated with nucleation of new domains, merging of growing domains [1]. Main regularities of the Barkhausen effect are related to the similar regularities of the polarization reversal processes of a crystal as a whole, although it may be only a small volume of the sample, which is switched in a jump-like way.…”

Stability of the single-domain state in single crystals of triglycine sulphate

“…Direct observation of the domains in triglycine sulfate crystals indicates that the Barkhausen jumps are due to the decay of the single domain state, the nucleation of new domains, and the closing of domain walls with a direction of spontaneous polarization opposite to the one in the crystal [1][2][3].…”