<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"><p>NH4H2PO4 nano-composite antiferroelectric materials in porous glass have been studied by means of dielectric and dilatometric investigations. Dielectric spectroscopy measurements in a wide frequency range are reported here for the first time, for both the antiferro- and paraelectric phases of ammonium dihydrogen phosphate (ADP) embedded in a porous matrix. Low frequency relaxation processes above the phase transition temperature were shown to occur. An investigation of the thermal expansion revealed a negative volume jump at the phase transition point. It was found that the phase transition temperature in ADP crystals embedded in porous glass decreased with the decrease of the mean pore size. The experimentally observed shift of the phase transition temperature is caused by a combination of size and pressure effects.</p></abstract>

NH4H2PO4 nano-composite antiferroelectric materials in porous glass have been studied by means of dielectric and dilatometric investigations. Dielectric spectroscopy measurements in a wide frequency range are reported here for the first time, for both the antiferro- and paraelectric phases of ammonium dihydrogen phosphate (ADP) embedded in a porous matrix. Low frequency relaxation processes above the phase transition temperature were shown to occur. An investigation of the thermal expansion revealed a negative volume jump at the phase transition point. It was found that the phase transition temperature in ADP crystals embedded in porous glass decreased with the decrease of the mean pore size. The experimentally observed shift of the phase transition temperature is caused by a combination of size and pressure effects.

Size effect and dielectric properties of NH4H2PO4 — porous glass composites

Institute of Physics, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland

Materials Science-Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Size effect and dielectric properties of NH4H2PO4 \u2014 porous glass composites"}

NH4H2PO4 nano-composite antiferroelectric materials in porous glass have been studied by means of dielectric and dilatometric investigations. Dielectric...

Size effect and dielectric properties of NH4H2PO4 — porous glass composites

Published Online: Jul 18, 2012

Page range: 143 - 150

DOI: https://doi.org/10.2478/s13536-012-0012-5

Keywords
size effect, ADP crystal, porous matrix, phase transition

© 2012 Wroclaw University of Technology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Size effect and dielectric properties of NH4H2PO4 — porous glass composites

Published Online: Jul 18, 2012

Page range: 143 - 150

DOI: https://doi.org/10.2478/s13536-012-0012-5

Keywordssize effect, ADP crystal, porous matrix, phase transition

© 2012 Wroclaw University of Technology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
size effect, ADP crystal, porous matrix, phase transition