| Project/Area Number |
24540383
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Condensed matter physics II
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| Research Institution | Sophia University |
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Principal Investigator |
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| Co-Investigator(Renkei-kenkyūsha) |
AKAHOSHI Daisuke 東邦大学, 理学部, 准教授 (90407354)
AKAKI Mitsuru 大阪大学, 大学院理学研究科, 助教 (60610904)
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Project Status |
Completed (Fiscal Year 2014)
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| Budget Amount *help |
¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2014: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2013: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2012: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
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| Keywords | 不純物置換 / 磁性 / 誘電性 / 結晶 / 酸化物 / 相転移 / マルチフェロイック / 磁場 / 強磁性 / アニール / 酸化還元処理 / 誘電体 / 不純物置換効果 / 反強磁性体 / 遷移金属酸化物 / スピン / 電気磁気効果 / 結晶構造解析 / 相共存 / 軌道整列 |
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| Outline of Final Research Achievements |
We have investigated the Mn-site substitution effect in Nd0.45Sr0.55MnO3 crystal, which has an A-type layered antiferromagnetic (A-AFM) phase with the 3dx2-y2-type orbital-order. Substitution of Fe or Ga for Mn-site suppresses both the A-AFM order and competing ferromagnetic (FM) correlation, whereas Cr substitution suppresses only the A-AFM order but reactivates the underlying FM correlation via double-exchange mechanism. In Nd0.45Sr0.55Mn0.95Cr0.05O3, the A-AFM state with the orbital-order is changed into the orbital-disordered three-dimensional FM metallic state by applying magnetic field of 12 T, which is much smaller than that of the parent compound.
In addition, We have studied impurity-doping effect in multiferroic CaBa(Co1-xFex)4O7 with 0≦x≦0.25. The magnetization curve shows that the magnetic moment sharply rises at 64K for x = 0 and 54K for x = 0.005, while it does not change for 0.0156≦x. This result indicates that the ferrimagnetic state disappears above 0.0156.
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