TRANSLATION - FOR REFERENCE ONLY -
August 3, 2026
An academic paper by one of our employees has been published in AIP (American Institute of Physics) Publishing’s Applied Physics Letters.
Applied Physics Letters is one of the most respected academic journals in applied physics, and publication in the journal is a significant honor for researchers worldwide. Research and development activities are essential to the KOKUSAI ELECTRIC Group’s sustainable growth, and we will continue to actively invest in R&D to develop high-value-added technologies and products that meet our customers’ needs.
About the Academic Paper by Our Employee Published in Applied Physics Letters
- Title
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Order-parameter-mediated stabilization of the ferroelectric orthorhombic phase in HfO2 by oxygen-vacancy-induced internal stress
- Author
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Tomoya Nagahashi, Saaya Kuroo, Naonori Akae, Hajime Karasawa
- Overview
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We investigated how oxygen vacancies influence the crystal-phase behavior of hafnium oxide (HfO₂), a material with strong potential for next-generation non-volatile memory. Using first-principles calculations, we found that oxygen vacancies do not directly stabilize the ferroelectric orthorhombic phase. Instead, they preferentially destabilize the competing monoclinic phase through internally generated stress, which indirectly promotes the formation of the ferroelectric orthorhombic phase. These results clarify the microscopic mechanism by which defects and stress interact to determine phase selection in HfO₂ and provide concrete design guidelines for improving ferroelectric HfO₂-based memory materials via controlled oxygen vacancy and stress engineering.
- DOI（Digital Object Identifier）
Under its corporate slogan “Technology & Tai-wa for Tomorrow,” the KOKUSAI ELECTRIC Group will continue to pursue economic, environmental, and social values through both its business activities and ESG initiatives (resolving environmental and social issues and strengthening governance), with the aim of contributing to the achievement of SDGs and realizing both a sustainable society and the group’s sustainable development.