1998 Fiscal Year Final Research Report Summary
Raman scattering study on Kondo semiconductors of CeRhSb and CeNiSn.
| Project/Area Number |
09640437
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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 | HIROSHIMA UNIVERSITY |
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Principal Investigator |
UDAGAWA Masayuki Hiroshima University, Faculty of Integrated Arts and Sciences, Professor, 総合科学部, 教授 (70144889)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Kondo semiconductors / Raman scattering / Phonon / Magnetic and Phonon interaction / Pseudo-Gap / Spin-Gap / Electronic Raman scattering |
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| Research Abstract |
The purpose of this research is to clarify the microscopic mechanism of the Kondo semiconductors of CeRhSb and CeNiSn by Raman scattering. The detailed polarization dependence of Raman scattering spectra has been measured in the temperature region between room temperature and 5K.The peaks, observed in the energy region between 0 and 250cm^-^1, are assigned as the phonons, judging from the results of the normal mode calculation. Among them, three phonons of CeRhSb and one of CeNiSn show the anomalous temperature dependence of their energy. Since these modes are the vibrations of Ce, the dependence shows the existence of the interaction between magnetic fluctuation and lattice vibration in the Kondo states. The broad background spectrum has been also observed in the Raman scattering spectra. Its intensity of the low energy region decreases below 30K.The spectral shape is well explained by the V-shaped state density of the pseudo-gap. The obtained parameters are similar to the reported values by specific heat and NMR.Such suppression of the hack-ground spectra of LaNiSn has not been observed. Therefore, the suppression of the low energy region of the back-ground spectra is originated from the appearance of the spin gap state due to the hybridization effect between the localized 4f and conduction electrons.
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