A training effect on electrical properties in nanoscale BiFeO₃

Abstract

Abstract. We report our observation of the training effect on dc electrical properties in a nanochain of BiFeO 3 as a result of large scale migration of defects under combined influence of electric field and Joule heating. We show that an optimum number of cycles of electric field within the range zero to ∼1.0 MV/cm across a temperature range 80-300 K helps in reaching the stable state via a glass-transition-like process in the defect structure. Further treatment does not give rise to any substantial modification. We conclude that such a training effect is ubiquitous in pristine nanowires or chains of oxides and needs to be addressed for applications in nanoelectronic devices.

Large magnetoelectric coupling in nanoscaleBiFeO3from direct electrical measurements

“…This could possibly be due to poor particle to particle connection which introduces surface effects. In fact, study of the dielectric spectroscopy on such a nanochain revealed presence of separate relaxation spectra for the interface and the bulk [19]. The suppression of polarization under a magnetic field observed in this direct electrical measurement on the nanochain is consistent with the results obtained from the neutron diffraction experiments [20,21].…”

Thickness, humidity, and polarization dependent ferroelectric switching and conductivity in Mg doped lithium niobate

“…Furthermore, an increase in currents after the 2nd cycle is apparent, which suggests training effects on electrical and/or ferroelectric behavior. [55][56][57] Apart from the aforementioned conduction due to inclined head-to-head domain walls near the tip that attract electrons, band bending can also play a role. If only polarization dependent band bending is taken into account, conducting Schottky contacts are formed when positive voltages are applied to the Àz domains and negative voltages to þz domains, which would lead to current flow at all voltages that are high enough to switch independent from polarity, contrary to the results.…”