Search

Ferroelectric properties of hafnium-based thin films have gained significant interest, yet the fundamental mechanisms responsible for the emergence of the ferroelectric phase continue to be inadequately investigated. In contrast with polycrystalline films fabricated by atomic layer deposition or sputter methods, which possess uncertainty in polarization orientation, epitaxial ferroelectric HfO2-based materials are less investigated, especially for factors such as electric field and oxygen vacancy, which are proposed and examined for their potential impacts on phase stability. In this study, Y-doped hafnium oxide (HYO) ferroelectric epitaxial films were fabricated using pulsed laser deposition, with variations in oxygen pressure during the deposition process. Structural and electrical analyses of HYO epitaxial ferroelectric films prepared under differing oxygen pressures revealed a correlation between the ferroelectric properties of the films and the oxygen content. An optimal selection of oxygen pressure was found to be conducive to the formation of HYO epitaxial ferroelectric films, presenting a promising avenue for future ferroelectric memory applications. [ABSTRACT FROM AUTHOR]

Ferroelectric properties of hafnium-based thin films have gained significant interest, yet the fundamental mechanisms responsible for the emergence of the ferroelectric phase continue to be inadequately investigated. In contrast with polycrystalline films fabricated by atomic layer deposition or sputter methods, which possess uncertainty in polarization orientation, epitaxial ferroelectric HfO2-based materials are less investigated, especially for factors such as electric field and oxygen vacancy, which are proposed and examined for their potential impacts on phase stability. In this study, Y-doped hafnium oxide (HYO) ferroelectric epitaxial films were fabricated using pulsed laser deposition, with variations in oxygen pressure during the deposition process. Structural and electrical analyses of HYO epitaxial ferroelectric films prepared under differing oxygen pressures revealed a correlation between the ferroelectric properties of the films and the oxygen content. An optimal selection of oxygen pressure was found to be conducive to the formation of HYO epitaxial ferroelectric films, presenting a promising avenue for future ferroelectric memory applications. [ABSTRACT FROM AUTHOR]

The discovery of nanoscale ferroelectricity in hafnia (HfO 2 ) has paved the way for next generation high-density, non-volatile devices. Although the surface conditions of nanoscale HfO 2 present one of the fundamental mechanism origins, the impact of external environment on HfO 2 ferroelectricity remains unknown. In this study, the deleterious effect of ambient moisture is examined on the stability of ferroelectricity using Hf 0.5 Zr 0.5 O 2 (HZO) films as a model system. It is found that the development of an intrinsic electric field due to the adsorption of atmospheric water molecules onto the film's surface significantly impairs the properties of domain retention and polarization stability. Nonetheless, vacuum heating efficiently counteracts the adverse effects of water adsorption, which restores the symmetric electrical characteristics and polarization stability. This work furnishes a novel perspective on previous extensive studies, demonstrating significant impact of surface water on HfO 2 -based ferroelectrics, and establishes the design paradigm for the future evolution of HfO 2 -based multifunctional electronic devices., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Objective: To explore the clinical effect of rapid massage at Shuidao (ST 28) to prevent puerpera from postpartum urinary retention., Methods: A total of 200 puerpera giving birth through vagina were enrolled and divided into an observation group and a control group according to the random number table method, 100 cases in each group. In the observation group, rapid massage at Shuidao (ST 28) was applied. In the control group,there was no intervention and urinated naturally. The traditional Chinese medicine syndrome scale was used to evaluate poor sense of urination, and record puerpera with or without postpartum urinary retention, the poor sense of first urination, the first time of urination, the amount of first urination and postpartum hemorrhage., Results: The poor sense of first urination in the observation group was significantly lower than that in the control ( P <0.001), the first time of urination in the observation group was significantly earlier than that in the control group ( P <0.001), the amount of first urination in the observation group was significantly more than that in the control group ( P <0.001), the observation group was superior to the control group to prevent postpartum urinary retention ( P <0.05)., Conclusion: Rapid massage at Shuidao (ST 28) can reduce the poor sense of first urination, significantly advance the time of spontaneous urination, significantly increase the amount of first urination and effectively prevent postpartum urinary retention.