Thermoelectric and Magnetic Properties of Pr₁₋<i>_x</i>Sr<i>_x</i>MnO₃ (0.1 ≦ <i>x</i> ≦ 0.7)

• Nakatsugawa Hiroshi

  Graduate School of Engineering, Yokohama National University

• Kubota Masaki

  Graduate School of Engineering, Yokohama National University

• Saito Miwa

  Department of Materials and Life Chemistry, Faculty of Engineering, Kanagawa University

Bibliographic Information

Other Title

• Thermoelectric and Magnetic Properties of Pr[1−x]Sr[x]MnO₃ (0.1≦x≦0.7)
• Thermoelectric and Magnetic Properties of Pr_1&minus;<i>_x</i>Sr<i>_x</i>MnO₃ (0.1 &lE; <i>x</i> &lE; 0.7)

Abstract

In this study, polycrystalline samples of Pr_1−xSr_xMnO₃ (0.1 ≦ x ≦ 0.7) were synthesized using a conventional solid-state reaction method. We investigated crystal structure, magnetic susceptibility (χ), and thermoelectric properties, such as electrical resistivity (ρ), Seebeck coefficient (S), and thermal conductivity (κ), as a function of temperature (T) or Sr content (x). The crystal structure at room temperature changed from orthorhombic Pbnm phases, with x ≦ 0.4, to tetragonal I4/mcm phases, with x ≧ 0.5. The samples for x ≦ 0.5 showed the ferromagnetic-like ground state below Curie temperature. Conversely, the samples for x = 0.5, 0.6, and 0.7 showed the charge-ordering ground state below 160 K, the A-type antiferromagnetic ground state below 310 K, and the C-type antiferromagnetic ground state below 318 K, respectively. Above room temperature, all the samples exhibited adiabatic small polaron conduction in a competition between the double exchange interaction and the Jahn-Teller distortion. Although the samples for x = 0.1 and 0.2 showed a large positive S below room temperature, the carrier type changed from hole-like to electron-like behavior above 1000 K and 500 K, respectively. Thus, all the samples for 0.1 ≦ x ≦ 0.7 showed a negative S at a high temperature. The largest dimensionless figure of merit (ZT) of all the samples above room temperature was 0.085 at 1073 K for x = 0.7, by a decrease in both ρ and lattice κ, and an increase in S. In addition, we obtained the largest ZT in the p-type specimens for x = 0.1, thus, attaining a maximum value of 0.0035 at 468 K. We discuss this behavior in terms of the potentiality to fabricate the oxide thermoelectric modules consisting of the same type of elements.

Journal

• MATERIALS TRANSACTIONS

  MATERIALS TRANSACTIONS 56 (6), 864-871, 2015

  The Japan Institute of Metals and Materials

Keywords

• thermoelectric properties
• magnetic properties
• adiabatic small polaron conduction
• double exchange interaction
• Jahn-Teller distortion
• Heikes formula

Details

• CRID: 1390282679230964864
• NII Article ID: 130005072160
• NII Book ID: AA1151294X
• DOI: 10.2320/matertrans.e-m2015807
• ISSN: 13475320
• ISSN: 13459678
• NDL BIB ID: 026412849
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I026412849
• Web Site: https://www.jstage.jst.go.jp/article/matertrans/56/6/56_E-M2015807/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed