2005 Fiscal Year Final Research Report Summary
Strange metamagnetism and magnetic transitions of TbCu_2Ge_2
| Project/Area Number |
16540323
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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 |
Condensed matter physics II
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| Research Institution | Yamaguchi University |
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Principal Investigator |
SHIGEOKA Toru Yamaguchi University, Faculty of Science, Professor, 理学部, 教授 (50167441)
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| Co-Investigator(Kenkyū-buntansha) |
UWATOKO Yoshiya University of Tokyo, Institute for Solid State Physics, Associate Professor, 物性研究所, 助教授 (40213524)
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| Project Period (FY) |
2004 – 2005
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| Keywords | TbCu2Ge2 / rare earth compound / metamagnetism / antiferromagnetism / magnetization process / magnetic susceptibility |
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| Research Abstract |
The tetragonal ternary compound TbCu_2Ge_2 shows a strange metamagnetic transition ; a metamagnetic transition, which appears in the hard magnetization [001] process, persists up to about 30 K above TN. This study has been carried out in order to understand the mechanism of this metamagnetic transition.
1.Single crystal Growth :
Some single crystal compounds have been grown to study physical properties and Neutron diffraction. The crystals are, however, too large mosaic to use the neutron diffraction. An attempt to growth a good crystal is now in progress.
2.Electrical resistivity :
Two anomalies are observed at TN=12.3 K and Tt=9 K in the temperature dependence of electrical resistivity. The way of transition shows the second order transition at TN and the first order one at Tt. No anomaly has been observed around 30 K where a broad peak appears in the magnetic susceptibility along the c-axis vs. temperature curve.
3.TbCu_2Si_2 single crystal :
The isomorphs single crystal compound TbCu_2Si_2 has been grown to study the magnetic properties. The comparison between those of the Ge and Si compound may lead better understanding for this strange metamagnetic transition. The magnetic behaviors of the Si compound is very similar to those of the Ge compound. The difference between Si and Ge does not affect the magnetic properties.
4.Analysis for Crystalline electric field effects
The CEF effects are very important for understanding the magnetic behaviors. From results of the magnetic susceptibility, magnetization and specific heart, the analysis is progress.
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