Effect of top electrode material on radiation-induced degradation of ferroelectric thin film structures

Abstract

The effects of gamma irradiation on the dielectric and piezoelectric responses of Pb[Zr0.52Ti0.48]O3 (PZT) thin film stacks were investigated for structures with conductive oxide (IrO2) and metallic (Pt) top electrodes. The samples showed, generally, degradation of various key dielectric, ferroelectric, and electromechanical responses when exposed to 2.5 Mrad (Si) 60Co gamma radiation. However, the low-field, relative dielectric permittivity, εr, remained largely unaffected by irradiation in samples with both types of electrodes. Samples with Pt top electrodes showed substantial degradation of the remanent polarization and overall piezoelectric response, as well as pinching of the polarization hysteresis curves and creation of multiple peaks in the permittivity-electric field curves post irradiation. The samples with oxide electrodes, however, were largely impervious to the same radiation dose, with less than 5% change in any of the functional characteristics. The results suggest a radiation-induced change in the defect population or defect energy in PZT with metallic top electrodes, which substantially affects motion of internal interfaces such as domain walls. Additionally, the differences observed for stacks with different electrode materials implicate the ferroelectric–electrode interface as either the predominant source of radiation-induced effects (Pt electrodes) or the site of healing for radiation-induced defects (IrO2 electrodes).

Application of Gel Method Ba2TiSi2O8 Ferroelectric Thin Film in Contemporary Handicraft Three-Dimensional Fiber Art Works

“…Ferroelectric materials refer to a class of materials with the ferroelectric effect, which is a branch of pyroelectric materials. e ferroelectric material is a kind of material with two or more spontaneous polarization directions, and its polarization energy changes with the change of the external electric field [8]. e crystal structure of most ferroelectric materials is the ABO 3 perovskite structure [9].…”

Application and Equipment of Preparation Technology of Ferroelectric Thin Film Materials in Sports Industry

“…The results show the radiation-induced changes in the number of defects or defect energy in the PZT with a metal top electrode. However, they did not consider the change and particularity of the dielectric constant of the PZT film after radiation, and there are still errors in the experiment [1]. Ferroelectric perovskite oxides are a promising photosensitive layer for photovoltaic applications due to their very high stability and the solar energy conversion mechanism associated with ferroelectrics they replace, which may lead to very high efficiency.…”

High-temperature X-ray scattering studies of atomic layer deposited IrO2

“…IrO 2 is also very conducting, its bulk resistivity being 35-60 m cm. Furthermore, it has superior fatigue properties (Okuyama, 2016;Tomczyk et al, 2017) and even radiation hardness (Brewer et al, 2016) over commonly used Pt electrodes.…”