| Project/Area Number |
25390133
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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 |
Quantum beam science
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| Research Institution | Japan Atomic Energy Agency |
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Principal Investigator |
YAMAUCHI Hiroki 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 物質科学研究センター, 研究副主幹 (50367827)
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| Research Collaborator |
WATANUKI Ryuta
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| Project Period (FY) |
2013-04-01 – 2017-03-31
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| Project Status |
Completed (Fiscal Year 2016)
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| Budget Amount *help |
¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
Fiscal Year 2015: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2014: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2013: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
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| Keywords | 磁気秩序 / 多極子秩序 / シャストリー・サザーランド格子 / 希土類化合物 / 中性子散乱 / 四極子秩序 / 八極子秩序 / モノクロメーター |
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| Outline of Final Research Achievements |
Neutron diffraction experiments were carried out to characterize the order parameters in an unknown intermediate phase, called phase II, of NdB4 showing three successive phase transitions. We found the antiferromagnetic (AFM) reflections with q0 = (0, 0, 0) in phase II. Group representation analysis was employed to deduce symmetry-allowed magnetic structures that were constrained with the crystal symmetry and the propagation vector(s) of the magnetic order. The magnetic reflections of powder diffraction patterns were successfully explained by postulating a coplanar structure with static magnetic moments in the tetragonal ab-plane. The magnetic structure in phase II was uniquely determined to be a linear combination of two noncolinear AFM structures. We propose that the quadrupolar interaction holds the key to stabilizing the noncollinear structure and quadrupolar order. Here, geometrical frustration would play an essential role in suppressing the dominance of the magnetic interaction.
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