Design of piezoelectric device materials by controlling nanostructure: First-principles calculations

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K04983
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Nanostructural physics
• Research Institution: Osaka University
• Principal Investigator: Momida Hiroyoshi 大阪大学, 産業科学研究所, 助教 (60634889)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 第一原理計算 / 圧電体 / ウルツ鉱構造 / ナノ構造

Outline of Final Research Achievements

Materials with wurtzite structures such as AlN and ZnO have been industrially important piezoelectric materials. However, one problem is that piezoelectric constants characterizing the material performance of them are several orders smaller than those of the perovskite-based materials. In this study, by using the computational materials science techniques based on the first-principles calculations, we theoretically show a guideline for materials design to enhance the piezoelectric constants of the wurtzite based piezoelectric materials. For the bulk materials, it is clarified that they generally have a strong relationship between the piezoelectric constants and the crystal structure parameters almost independent of constituent elements. For the nanostructure wurtzite materials, it is also found that atomic structures, electronic structures, and piezoelectric properties of them show peculiar changes depending on the sizes of nanostructure and external strains.

Free Research Field

計算材料科学

Academic Significance and Societal Importance of the Research Achievements

圧電材料は電子デバイスやセンサー・アクチュエータなどの電気ー機械エネルギー変換素子として広く産業利用されており、近年では将来のピエゾ発電やピエゾエレクトロニクス素子における材料としての期待も大きい。これらの応用において、ウルツ鉱構造系圧電材料は重要な役割をもつが、その性能指標のひとつである圧電定数を高めるための材料設計指針は明確でないことが大きな問題であった。本研究により、広い物質範囲への適用が可能な高圧電化の材料設計指針のひとつが示され、新規材料開発の加速に資する成果が得られた。材料の圧電性に対する元素置換や原子配列・ナノ構造化に関する理論的理解が進められた。