Electronic structure and transport properties of SrAl2Si 2: Effect of yttrium substitution

C. S. Lue; C. P. Fang; A. C. Abhyankar; J. W. Lin; H. W. Lee; C. M. Chang; Y. K. Kuo

doi:10.1016/j.intermet.2011.05.009

Electronic structure and transport properties of SrAl₂Si ₂: Effect of yttrium substitution

C. S. Lue, C. P. Fang, A. C. Abhyankar, J. W. Lin, H. W. Lee, C. M. Chang, Y. K. Kuo

Department of Physics

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9 Citations (Scopus)

Abstract

We report the results of yttrium substitution on the electrical resistivity (ρ), the thermal conductivity (κ), as well as the Seebeck coefficient (S) of the Sr_1-xY_xAl₂Si₂ alloys with 0 ≤ x ≤ 0.20. Both ρ(T) and S(T) data suggest that SrAl ₂Si₂ is a semimetallic, low charge carrier density system with a pseudogap at the Fermi level density of states (DOS). Upon substituting Y onto the Sr sites, the electrical resistivity and the absolute value of the Seebeck coefficient decrease significantly. Such an observation can be associated with the modification of the electronic band structure due to electron doping via Y substitution. Analysis of the thermal conductivity reveals the contribution of various thermal scattering mechanisms through chemical substitution. Theoretical studies with density functional theory are also employed to investigate the electronic band structure of Sr_1-xY _xAl₂Si₂. It is revealed that SrAl ₂Si₂ possesses a shallow DOS at the Fermi level with both n-type and p-type charge carriers. Upon Y substitution a shift in the Femi level occurs such that the Sr_1-xY_xAl₂Si₂ system becomes more metallic with increasing x, being consistent with the experimental findings.

Original language	English
Pages (from-to)	1448-1454
Number of pages	7
Journal	Intermetallics
Volume	19
Issue number	10
DOIs	https://doi.org/10.1016/j.intermet.2011.05.009
Publication status	Published - 2011 Oct

All Science Journal Classification (ASJC) codes

General Chemistry
Mechanics of Materials
Mechanical Engineering
Metals and Alloys
Materials Chemistry

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10.1016/j.intermet.2011.05.009

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title = "Electronic structure and transport properties of SrAl2Si 2: Effect of yttrium substitution",

abstract = "We report the results of yttrium substitution on the electrical resistivity (ρ), the thermal conductivity (κ), as well as the Seebeck coefficient (S) of the Sr1-xYxAl2Si2 alloys with 0 ≤ x ≤ 0.20. Both ρ(T) and S(T) data suggest that SrAl 2Si2 is a semimetallic, low charge carrier density system with a pseudogap at the Fermi level density of states (DOS). Upon substituting Y onto the Sr sites, the electrical resistivity and the absolute value of the Seebeck coefficient decrease significantly. Such an observation can be associated with the modification of the electronic band structure due to electron doping via Y substitution. Analysis of the thermal conductivity reveals the contribution of various thermal scattering mechanisms through chemical substitution. Theoretical studies with density functional theory are also employed to investigate the electronic band structure of Sr1-xY xAl2Si2. It is revealed that SrAl 2Si2 possesses a shallow DOS at the Fermi level with both n-type and p-type charge carriers. Upon Y substitution a shift in the Femi level occurs such that the Sr1-xYxAl2Si2 system becomes more metallic with increasing x, being consistent with the experimental findings.",

author = "Lue, {C. S.} and Fang, {C. P.} and Abhyankar, {A. C.} and Lin, {J. W.} and Lee, {H. W.} and Chang, {C. M.} and Kuo, {Y. K.}",

note = "Funding Information: The authors would like to thank the National Science Council of Taiwan for financially supporting this research under Contract Nos NSC-97-2628-M-259-001-MY3 (YKK) , NSC 98-2112-M-259-003-MY3(CMC) and NSC-98-2112-M-006-011-MY3 (CSL) . The theoretical work was supported by the National Center for Theoretical Sciences and the National Center for High Performance Computing of Taiwan.",

year = "2011",

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doi = "10.1016/j.intermet.2011.05.009",

language = "English",

volume = "19",

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T1 - Electronic structure and transport properties of SrAl2Si 2

T2 - Effect of yttrium substitution

AU - Lue, C. S.

AU - Fang, C. P.

AU - Abhyankar, A. C.

AU - Lin, J. W.

AU - Lee, H. W.

AU - Chang, C. M.

AU - Kuo, Y. K.

N1 - Funding Information: The authors would like to thank the National Science Council of Taiwan for financially supporting this research under Contract Nos NSC-97-2628-M-259-001-MY3 (YKK) , NSC 98-2112-M-259-003-MY3(CMC) and NSC-98-2112-M-006-011-MY3 (CSL) . The theoretical work was supported by the National Center for Theoretical Sciences and the National Center for High Performance Computing of Taiwan.

PY - 2011/10

Y1 - 2011/10

N2 - We report the results of yttrium substitution on the electrical resistivity (ρ), the thermal conductivity (κ), as well as the Seebeck coefficient (S) of the Sr1-xYxAl2Si2 alloys with 0 ≤ x ≤ 0.20. Both ρ(T) and S(T) data suggest that SrAl 2Si2 is a semimetallic, low charge carrier density system with a pseudogap at the Fermi level density of states (DOS). Upon substituting Y onto the Sr sites, the electrical resistivity and the absolute value of the Seebeck coefficient decrease significantly. Such an observation can be associated with the modification of the electronic band structure due to electron doping via Y substitution. Analysis of the thermal conductivity reveals the contribution of various thermal scattering mechanisms through chemical substitution. Theoretical studies with density functional theory are also employed to investigate the electronic band structure of Sr1-xY xAl2Si2. It is revealed that SrAl 2Si2 possesses a shallow DOS at the Fermi level with both n-type and p-type charge carriers. Upon Y substitution a shift in the Femi level occurs such that the Sr1-xYxAl2Si2 system becomes more metallic with increasing x, being consistent with the experimental findings.

AB - We report the results of yttrium substitution on the electrical resistivity (ρ), the thermal conductivity (κ), as well as the Seebeck coefficient (S) of the Sr1-xYxAl2Si2 alloys with 0 ≤ x ≤ 0.20. Both ρ(T) and S(T) data suggest that SrAl 2Si2 is a semimetallic, low charge carrier density system with a pseudogap at the Fermi level density of states (DOS). Upon substituting Y onto the Sr sites, the electrical resistivity and the absolute value of the Seebeck coefficient decrease significantly. Such an observation can be associated with the modification of the electronic band structure due to electron doping via Y substitution. Analysis of the thermal conductivity reveals the contribution of various thermal scattering mechanisms through chemical substitution. Theoretical studies with density functional theory are also employed to investigate the electronic band structure of Sr1-xY xAl2Si2. It is revealed that SrAl 2Si2 possesses a shallow DOS at the Fermi level with both n-type and p-type charge carriers. Upon Y substitution a shift in the Femi level occurs such that the Sr1-xYxAl2Si2 system becomes more metallic with increasing x, being consistent with the experimental findings.

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Electronic structure and transport properties of SrAl₂Si ₂: Effect of yttrium substitution

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