Phenomenological Model for Defect Interactions in Irradiated Functional Materials

Abstract

The ability to tailor the performance of functional materials, such as semiconductors, via careful manipulation of defects has led to extraordinary advances in microelectronics. Functional metal oxides are no exception – protonic-defect-conducting oxides find use in solid oxide fuel cells (SOFCs) and oxygen-deficient high-temperature superconductors are poised for power transmission and magnetic imaging applications. Similarly, the advantageous functional responses in ferroelectric materials that make them attractive for use in microelectromechanical systems (MEMS), logic elements, and environmental energy harvesting, are derived from interactions of defects with other defects (such as domain walls) and with the lattice. Chemical doping has traditionally been employed to study the effects of defects in functional materials, but complications arising from compositional heterogeneity often make interpretation of results difficult. Alternatively, irradiation is a versatile means of evaluating defect interactions while avoiding the complexities of doping. Here, a generalized phenomenological model is developed to quantify defect interactions and compare material performance in functional oxides as a function of radiation dose. The model is demonstrated with historical data from literature on ferroelectrics, and expanded to functional materials for SOFCs, mixed ionic-electronic conductors (MIECs), He-ion implantation, and superconductors. Experimental data is used to study microstructural effects on defect interactions in ferroelectrics.

Large recoverable energy density with excellent thermal stability in Mn‐modified NaNbO3‐CaZrO3 lead‐free thin films

“…As a result, the peak is shifted to lower frequency. Nevertheless, newly formed oxygen vacancies resulting from excessive Mn doping (i.e., 2 mol%) may strengthen the defect interaction and increase the number of mobile V O ¨. Thus, the peak is back to higher frequency.…”

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.…”

Impact of Radiation Effect on Ferroelectric Al-Doped HfO2 Metal-Ferroelectric- Insulator-Semiconductor Structure

“…It has verified that interface defects have been formed in the TiN/HfO2/Si MOS capacitor during irradiation, and the accumulation capacitance decreased with the increasing of irradiation dose [13]. Brewer et al indicated that the radiation effect can be also influenced by orientation, domain size, grain boundary density and morphology [14][15]. C. Palade et al [16] demonstrated that the trilayer of control HfO2/floating gate of Ge nanoparticles in HfO2/tunnel HfO2/Si substrate containing HfO2 nanocrystals with the orthorhombic/tetragonal structure has a high sensitivity of 0.8 mV Gy −1 to α particle irradiation.…”