Innovative refrigerator using magnetic entropy change induced by electric field

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K13945
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Electronic materials/Electric materials
• Research Institution: Nagoya Institute of Technology
• Principal Investigator: Gomi Manabu 名古屋工業大学, 工学(系)研究科(研究院), 教授 (80126276)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: マルチフェロイックス / 磁気冷却 / 磁気エントロピー / ビスマスフェライト / 構造相転移 / 結晶対称性 / 擬正方晶 / 菱面体晶

Outline of Final Research Achievements

Crystallographic change induced by substituting Ga for Fe of rhombohedral ferroelectric antiferromagnet BiFeO3 has been investigated in detail for powder samples synthesized using a novel sol-gel route at ambient pressure and low temperature. The crystal structure changed from rhombohedral (R) to pseudo-tetragonal (T-like) at Ga substitution of 0.1-0.2 per a formula unit. The magnetic order temperature of the T-like phase reduced to 140 K. This means that the magnetic order can be changed from antiferromagnetic to paramagnetic by the R-T phase transition at room temperature. It was shown that the bulk ceramics permitting us to apply an electric field can be prepared using the plasma-sintering method.

Free Research Field

電子物性工学