Project/Area Number |
22651044
|
Research Category |
Grant-in-Aid for Challenging Exploratory Research
|
Allocation Type | Single-year Grants |
Research Field |
Nanomaterials/Nanobioscience
|
Research Institution | Saga University |
Principal Investigator |
|
Project Period (FY) |
2010 – 2012
|
Project Status |
Completed (Fiscal Year 2012)
|
Budget Amount *help |
¥3,440,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥240,000)
Fiscal Year 2011: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2010: ¥2,400,000 (Direct Cost: ¥2,400,000)
|
Keywords | 新物質 / 幾何学的フラストレーション / 新奇磁気電気特性 / マルチフェロ物質 / ナノ粒子 / 熱膨張 / 磁気相転移 / 磁気格子相関 / 誘電特性 / 新規ナノ物性 / 巨大負熱膨張 / ナノ磁性体 |
Research Abstract |
Hydroxyl salts of the type M2(OH)3X, and M(OH)X, where M represents a transition metal ion and X represents a halogen ion, widely exist as minerals and were recently reported to be geometrically frustrated magnets. Here we report the finding of ferroelectric response in them. First, we observed strong magnetic-lattice-dielectric couplings in all of them as witnessed during their magnetic transitions at low temperatures. Secondly, we identified apparent ferroelectric responses in the deuterated hydroxyl salts of high crystal symmetries, i.e., rhombohedral Co2(OD)3Cl and Co2(OD)3Br, at high temperatures of 220--230 K through an isotope effect. The present work shows that multiferroicity may be a potentially universal phenomenon in magnetic hydroxyl salts. Meanwhile, it provides the first link between magnetic geometric frustration and hydrogen-bonded soft-mode ferroelectrics.
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