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Title: Pressure-induced shift of effective Ce valence, Fermi energy and phase boundaries in CeOs 4 Sb 12

CeOs4Sb12, a member of the skutterudite family, has an unusual semimetallic low-temperatureL-phase that inhabits a wedge-like area of the fieldH—temperatureTphase diagram. We have conducted measurements of electrical transport and megahertz conductivity on CeOs4Sb12single crystals under pressures of up to 3 GPa and in high magnetic fields of up to 41 T to investigate the influence of pressure on the differentHTphase boundaries. While the high-temperature valence transition between the metallicH-phase and theL-phase is shifted to higherTby pressures of the order of 1 GPa, we observed only a marginal suppression of theS-phase that is found below 1 K for pressures of up to 1.91 GPa. High-field quantum oscillations have been observed for pressures up to 3.0 GPa and the Fermi surface of the high-field side of theH-phase is found to show a surprising decrease in size with increasing pressure, implying a change in electronic structure rather than a mere contraction of lattice parameters. We evaluate the field-dependence of the effective masses for different pressures and also reflect on the sample dependence of some of the properties of CeOs4Sb12which appears to be limited more » to the low-field region.

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Award ID(s):
1905636 1810310
Publication Date:
Journal Name:
New Journal of Physics
Page Range or eLocation-ID:
Article No. 043044
IOP Publishing
Sponsoring Org:
National Science Foundation
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