| Project/Area Number |
12640355
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
固体物性Ⅱ(磁性・金属・低温)
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| Research Institution | TOKYO METROPOLITAN UNIVERSITY |
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Principal Investigator |
MANIWA Yutaka FACULTY OF SCIENCE, TOKYO METROPOLITAN UNIVERSITY, PROFESSOR, 理学研究科, 助教授 (70173937)
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| Co-Investigator(Kenkyū-buntansha) |
TOU Hideki FACULTY OF SCIENCE, TOKYO METROPOLITAN UNIVERSITY, RESEARCH ASSOCIATE, 理学研究科, 助手 (60295467)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥4,200,000 (Direct Cost: ¥4,200,000)
Fiscal Year 2001: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2000: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | zeolite / ferromagnetism / NMR / mass density wave / orbital order / XRD / magnetism |
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| Research Abstract |
K-ion type zeolite LTA (K_<12>Al_<12>Si_<12>O_<48>(H_2O)_n, which is abbreviated to K_<12>-LTA), is one of synthetic hydrated aluminosilicates. Its framework consist of SiO_4 and AlO_4 tetrahedra sharing the oxygen atom each other and forms two kinds of cage called α and β. These cages are nested each other and form a cubic lattice with a lattice constant 1.23nm. It was found that this system undergoes a phase transition to a ferromagnetic (FM)-like state below around 7K when additional K-atoms are loaded into well-dehydrated K-ion type LTA. K_x/K_<12>-LTA, where x is the number of additional K atoms per α- (or β-) cage. We investigated the structure and magnetism in this system. The main results are summarized below.
1. Magnetic and structural phase diagram was established in loading density 0< x<7 and temperature rage 2K<T<500K.
2. We performed ^<29>Si-NMR and μSR experiments in K_x/K_<12>-LTA. The data clearly showed the magnetic transition as bulk properties.
3. We proposed the most probable magnetic structure which is a canted type II antiferromagnetism in face centered cubic lattice with spin S=1.
4. We discovered a new thermally chromatic phenomenon in Na-type zeolite FAU.
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