Containerless Processing of White and Red Phosphors with Novel Crystal Structures and Unique Coordination Polyhedral Distortions

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K15284
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: Tohoku University
• Principal Investigator: Fukushima Jun 東北大学, 工学研究科, 助教 (80634063)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 蛍光体 / 無容器浮遊法

Outline of Final Research Achievements

In this study, a new metastable white phosphor was prepared by using the quenching effect of containerless processing. Novel gas-floating containerless processing system have been developed. The device can control the cooling rate and synthesized a new metastable phase in the La-W-O system, which shows white fluorescence near the eutectic composition of about 80 mol% WO3 in the La2O3-WO3 phase diagram. The metastable phase was estimated to be slightly richer in La than the eutectic composition from the compositional study experiments. The sample containing this metastable phase showed white fluorescence with a high red component than that of CaWO4.

Free Research Field

材料プロセッシング

Academic Significance and Societal Importance of the Research Achievements

物質探索空間を拡大するという点で、冷却速度をコントロール可能なガス浮遊型無容器プロセッシング装置の開発ができたことは意義深い。また、実際に準安定新規蛍光体が合成し、物質探索空間の拡張が可能となることを実証した点で学術的意義がある。また、演色性の高い白色蛍光体の創出は将来的に照明の省エネルギー化につながると考えられ、社会的意義のあるものと考える。