Polarization fatigue in PbZr0.45Ti0.55O3-based capacitors studied from high resolution synchrotron x-ray diffraction

Abstract

High resolution synchrotron x-ray diffraction experiments were performed on (111)-oriented PbZr0.45Ti0.55O3-based capacitors with a composition in the morphotropic region. Diffraction analyzes were done after bipolar pulses were applied and removed, representing several places in the cyclic switching. Microstructural changes were evidenced from relative diffracted intensities variations of several Bragg reflections and a correlation with the evolution of the ferroelectric responses has been established. First, a peculiar microstructural evolution was observed during the first 3×104 switching cycles and was attributed to the so-called “wake-up” effect. On the other hand, the onset of the fatigue phenomenon was accompanied by significant variations on integrated diffraction intensities. Several mechanisms are proposed and discussed to explain such variations. Finally, the ferroelectric responses were analyzed after x-ray diffraction experiments and compared with those measured before exposure. A detailed analysis has shown that both domain configuration and switching process are strongly influenced by x-ray irradiation. It can be considered that x rays act as a “revealer” of the domain structure created during the preceding electrical treatment.

Physical Mechanisms behind the Field‐Cycling Behavior of HfO2‐Based Ferroelectric Capacitors

“…Wake-up studies on PZT material system were performed and reported before. [15,29,30] On the other hand, a very detailed and systematic review of fatigue mechanisms was reported by Tagantsev et al in 2001 [17] and Lou et al in 2009. [31] These studies suggested that a combination of several mechanisms (domain de-/ pinning, [32] seed inhibition, [33] and formation of the passive/ dead layer [34] ) could be responsible for the device wake-up and fatigue.…”

“…The initial increase in the MW observed up to 10 3 cycles correlates with the "wake-up" effect as reported elsewhere. [15,16,20] With further field cycling, the continuous switching of the polarization state reduces the MW.…”

“…This increase of the remnant polarization, P r value corresponds with an opening or de-pinching of the pristine pinched hysteresis loop with field cycling, [15,16] ; (ii) "Fatigue" or aging: after a certain number of cycles, the remnant polarization hysteresis decreases resulting in a closure of the memory window (difference between positive and negative remnant polarization) due to aging mechanisms. [17] Wake-up and fatigue behaviors are due to a complex interplay among phenomena involving the ferroelectric properties (e.g., domain orientation, phase stability and field induced phase transitions) and dielectric characteristics (e.g., defect activation/creation, charge injection and consequent trapping), that could induce a built-in bias.…”

Reliable polarization switching of BiFeO 3

“…The additional peaks for BiFeO 3 indicate that new ferroelastic domains formed during fatigue cycles and that fatigued (111) pc BiFeO 3 films have four ferroelastic variances. Previously, there were reports on fatigue characteristics of rhombohedral ferroelectrics: ferroelastic domain evolution with polarization fatigue in textured films [43,44] and ceramics [45,46] of PZN-PT, which are initially multi-domain states. However, these new ferroelastic domains are nucleated from the initial monodomain state with fatigue in our work.…”

In situsynchrotron diffraction investigation of morphotropicPb[Zr1−xTix]OSchönau1, Knapp2, Kungl3 et al. 2007Phys. Rev. B714450View full textAdd to dashboardCite

“…Domain switching was calculated from changes in integral intensities and lattice changes from peak shifts. 15,[19][20][21][22][23][24][25][26] Besides the work of Menou et al, 21 all these studies focused on donor doped material. For compositions close to the MPB mostly the model of a coexistence of a tetragonal and rhombohedral phase 26 or a tetragonal and monoclinic phase 23 was assumed and analyzes concentrated on the measurement of the pseudocubic ͕111͖ c and ͕200͖ c reflections assuming constant phase contents.…”