Phase transitions and ferroelectricity in NaSb$_{3}$F$_{10}$

ORAL

Abstract

The structural prediction that NaSb$_3$F$_{10}$ is a new ferroelectric has been confirmed experimentally. The mean phase transition temperature $T_{\mbox{c}}$ $\approx$ 461 K with an associated entropy change $\sim$6 J mol$^{-1}$ K$^{-1}$. The colorless crystals melt at $T_{\mbox{m}}$ $\sim$515 K with decomposition starting at $\sim$600 K. A thermal hysteresis in $T_{\mbox{c}}$ of $\sim$35 K between heating and cooling at 25 K min$^{-1}$ is typical of a first order phase transition. The space group in ferroelectric phase III is $P6_3$, that in the predicted antiferroelectric phase II is $P6_3$22, a supergroup of $P6_3$. The space group of prototypic nonferroic phase I is supergroup $P6_3/mmc$, of which the space group of phase III is not a subgroup. The dielectric permittivity at 100 Hz increases more than an order of magnitude from 350 K before undergoing a major inflection at $T_{\mbox{c}}$ = 460(10) K; it increases thereafter to $T_{\mbox{m}}$. The dielectric loss at 100 Hz is low but increases an order of magnitude from its value at $\sim$350 K before undergoing an inflection at $\sim$460 K, also rising steadily thereafter to $T_{\mbox{m}}$. The reproducible dielectric hysteresis loop, with $P_{\mbox{s}}$ $\approx$ 20$\mu$ C m$^{-2}$ at room temperature under the application of 0.3 MV m$^{-1}$ a.c. or greater, unambiguously verifies the predicted ferroelectric property. The pyroelectric coefficient $\langle{p}\rangle$ = 17(5)$\mu$ C m$^{-2}$ K$^{-1}$ at 298 K.

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Authors

  • Peter Wu

    Southern Oregon University

  • Panos Photinos

    Southern Oregon University

  • Sidney Abraham

    Southern Oregon University

  • Ernest Henley

    Green River College, University of British Columbia, Pacific Northwest National Laboratory, BYU-Idaho Dept. of Physics, University of Washington, Applied Physics Technologies, Inc., Montana State University, Universidade Estadual de Campinas, Southern Oregon University, Oregon State University Department of Physics, Oregon State University Department of Chemistry, National Institute of Standards and Technology Center for Neutron Research, Physics Department, Oregon State University, University of Idaho, University of Wyoming, Department of Physics, Montana State University, University of Portland, Idaho State University, WWU, Advanced Light Source, Lawrence Berkeley National Laboratory, Oregon Center for Optics and Department of Physics, University of Oregon, Lewis and Clark, Queen's University, University of Notre Dame, Idaho National Lab, TRIUMF, RCNP, Japan, University of Guelph, Mexico University, St. Mary's University, University of Montreal, Deep River, Dept. of Physics; Montana State University, Dept. of Plant Sciences and Pathology, Dept. of Chem. and Biochem.; Montana State University, Department of Physics, Shandong University, P. R. China, Department of Physics, University of Idaho, USA, Dept. of Physics, Simon Fraser University, Burnaby, BC V5A 1S6 Canada, University of Calgary

  • Ernest Henley

    Green River College, University of British Columbia, Pacific Northwest National Laboratory, BYU-Idaho Dept. of Physics, University of Washington, Applied Physics Technologies, Inc., Montana State University, Universidade Estadual de Campinas, Southern Oregon University, Oregon State University Department of Physics, Oregon State University Department of Chemistry, National Institute of Standards and Technology Center for Neutron Research, Physics Department, Oregon State University, University of Idaho, University of Wyoming, Department of Physics, Montana State University, University of Portland, Idaho State University, WWU, Advanced Light Source, Lawrence Berkeley National Laboratory, Oregon Center for Optics and Department of Physics, University of Oregon, Lewis and Clark, Queen's University, University of Notre Dame, Idaho National Lab, TRIUMF, RCNP, Japan, University of Guelph, Mexico University, St. Mary's University, University of Montreal, Deep River, Dept. of Physics; Montana State University, Dept. of Plant Sciences and Pathology, Dept. of Chem. and Biochem.; Montana State University, Department of Physics, Shandong University, P. R. China, Department of Physics, University of Idaho, USA, Dept. of Physics, Simon Fraser University, Burnaby, BC V5A 1S6 Canada, University of Calgary