Effects of crystallization interfaces on irradiated ferroelectric thin films

Abstract

This work investigates the role of crystallization interfaces and chemical heterogeneity in the radiation tolerance of chemical solution-deposited lead zirconate titanate (PZT) thin films. Two sets of PZT thin films were fabricated with crystallization performed at (i) every deposited layer or (ii) every three layers. The films were exposed to a range of 60Co gamma radiation doses, between 0.2 and 20 Mrad, and their functional response was compared before and after irradiation. The observed trends indicate enhancements of dielectric, ferroelectric, and piezoelectric responses at low radiation doses and degradation of the same at higher doses. Response enhancements are expected to result from low-dose (≤2 Mrad), ionizing radiation-induced charging of internal interfaces—an effect that results in neutralization of pre-existing internal bias in the samples. At higher radiation doses (>2 Mrad), accumulation and self-ordering of radiation-modified, mobile, oxygen vacancy-related defects contribute to degradation of dielectric, ferroelectric, and piezoelectric properties, exacerbated in the samples with more crystallization layers, potentially due to increased defect accumulation at these internal interfaces. These results suggest that the interaction between radiation and crystallization interfaces is multifaceted—the effects of ionization, domain wall motion, point defect mobility, and microstructure are considered.

Emergence of Rapid Oxygen Surface Exchange Kinetics during in Situ Crystallization of Mixed Conducting Thin Film Oxides

“…For example, Heiroth et al have reported that crystallization temperatures can be decreased by annealing amorphous thin films, compared with directly depositing highly crystalline thin films by PLD . Crystallization studies of piezoelectric lead zirconate titanate thin films − and ionically conducting yttria-stabilized zirconia (YSZ) , or ceria-based thin films − have focused on the crystallization kinetics and thermally driven microstructural evolution, including microstrain and grain growth kinetics and stagnation …”

The effects of proton radiation on aluminum oxide/zirconium-doped hafnium oxide stacked ferroelectric tunneling junctions

“…The good performance of traditional perovskite-based ferroelectric memory (FeRAM) in extreme environments makes it promising for aerospace and nuclear applications. [8][9][10][11][12] Hence, the space applications of the emerging hafnium-based FeRAM are also of interest. It is necessary to systematically evaluate the radiation effects of its materials, devices, and circuits before its application.…”

A Comparative Study of the γ‐Ray Radiation Effect on Zr‐Doped and Al‐Doped HfO2‐Based Ferroelectric Memory

“…The γ‐ray radiation will induce trapped defects and compensate a part of internal defects, resulting in a weakened domain unpinning effect. Meanwhile, the radiation effect should be influenced by domain size, orientation, grain boundary density, and morphology, as reported by Brewer et al The different ratios of phase structure and grain boundary in HfAlO‐20 thin films may induce a relative change during fatigue tests, as shown in Figure c.…”