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We present a comprehensive series of results of electrical transport (electrical conductivity, magnetoconductivity, Hall effect), thermal (specific heat), and optical (reflectivity) measurements in varying temperature ranges between 1.5 and 300 K on high-quality single-grain quasicrystals of icosahedral Y-Mg-Zn. This data set is augmented by the specific-heat and optical-reflectivity data obtained from a single-grain quasicrystal of icosahedral Tb-Mg-Zn. For Y-Mg-Zn, both the electrical conductivity {sigma}(T) and magnetoconductivity {delta}{sigma}(H) may be described by calculations considering quantum interference effects. A detailed comparison of the weak-localization contributions to {sigma}(T) and {delta}{sigma}(H) with our experimental data provides estimates of the inelastic and spin-orbit relaxation rates. The inelastic relaxation rate is found to be proportional to T{sup 3}. The dominant contributions to the optical conductivity {sigma}{sub 1}({omega}) spectrum, obtained from the reflectivity R({omega}) data in the frequency range between 16 and 9.7x10{sup 4} cm{sup -1}, are a strong Drude feature at low frequencies and a prominent absorption signal centered at approximately 6x10{sup 3} cm{sup -1}. A comparison of the spectral weight of the Drude contribution to {sigma}{sub 1}({omega}) with the magnitude of the linear-in-T term {gamma}T of the low-temperature specific heat C{sub p}(T) yields the itinerant charge-carrier density n{sub i}=7.62x10{sup 21} cm{sup -3} or 0.13 charge carriers per atom. The low n{sub i} value is corroborated by the results of the Hall effect measurements. For Tb-Mg-Zn, the optical conductivity {sigma}{sub 1}({omega}) spectrum reveals features similar to those of Y-Mg-Zn. The low-temperature specific heat C{sub p}(T) of Tb-Mg-Zn is strongly influenced by a spin-glass-type freezing of Tb moments and by crystal-electric-field effects. (c) 2000 The American Physical Society.
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| Authors: |
Chernikov, M. A. [Laboratorium fuer Festkoerperphysik, Eidgenoessische Technische Hochschule-Zuerich, 8093 Zuerich, (Switzerland)];
Paschen, S. [Laboratorium fuer Festkoerperphysik, Eidgenoessische Technische Hochschule-Zuerich, 8093 Zuerich, (Switzerland)];
Felder, E. [Laboratorium fuer Festkoerperphysik, Eidgenoessische Technische Hochschule-Zuerich, 8093 Zuerich, (Switzerland)];
Vorburger, P. [Laboratorium fuer Festkoerperphysik, Eidgenoessische Technische Hochschule-Zuerich, 8093 Zuerich, (Switzerland)];
Ruzicka, B. [Laboratorium fuer Festkoerperphysik, Eidgenoessische Technische Hochschule-Zuerich, 8093 Zuerich, (Switzerland)];
Degiorgi, L. [Laboratorium fuer Festkoerperphysik, Eidgenoessische Technische Hochschule-Zuerich, 8093 Zuerich, (Switzerland)];
Ott, H. R. [Laboratorium fuer Festkoerperphysik, Eidgenoessische Technische Hochschule-Zuerich, 8093 Zuerich, (Switzerland)];
Fisher, I. R. [Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)];
Canfield, P. C. [Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)]
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| Publication Date: | 2000 Jul 01 |
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| OSTI Identifier: | 20217103 |
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| Resource Type: | Journal Article |
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| Resource Relation: | Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 62; Journal Issue: 1; Other Information: PBD: 1 Jul 2000 |
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| Country of Publication: | United States |
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| Language: | English |
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| Format: | Size: page(s) 262-272 |
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| Other Number(s): | Journal ID: ISSN 1098-0121; TRN: US00Z2148 |
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| Subject: | 36 MATERIALS SCIENCE; YTTRIUM; TERBIUM ALLOYS; YTTRIUM ALLOYS; ZINC ALLOYS; MAGNESIUM ALLOYS; OPTICAL PROPERTIES; HALL EFFECT; CRYSTALS; SPECIFIC HEAT; REFLECTIVITY; MAGNETORESISTANCE; ELECTRIC CONDUCTIVITY; CHARGED-PARTICLE TRANSPORT; TEMPERATURE RANGE 0000-0013 K; TEMPERATURE RANGE 0013-0065 K; TEMPERATURE RANGE 0065-0273 K; SPIN GLASS STATE; CRYSTAL FIELD; ELECTRIC FIELDS; EXPERIMENTAL DATA |
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| Update Date: | 2010 Jun 03 |
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