PASCUAL-GONZALEZ, Cristina, SCHILEO, Giorgio and FETEIRA, Antonio (2016). Band gap narrowing in ferroelectric KNbO3-Bi(Yb,Me)O3 (Me=Fe or Mn) ceramics. Applied Physics Letters, 109 (13).
PDF (Replace with published after 12 month embargo)
accepted_manuscript.pdf - Accepted Version
Available under License All rights reserved.
Download (1MB) | Preview
PDF (Acceptance e-mail)
Feteira - 13536.pdf - Other
Restricted to Repository staff only
The direct optical band gap in ferroelectric KNbO3-Bi(Yb,Me)O3 (Me=Fe or Mn) ceramics fabricated by the solid state reaction method varies from 3.2 eV for KNbO3 down to 2.2 eV for 0.95KNbO3-0.05BiYbO3, as revealed by optical spectroscopic ellipsometry. This narrowing of band gap is accompanied by an apparent increase of the room-temperature relative permittivity from 320 for KNbO3 to 900 for 0.95KNbO3-0.05BiYbO3. All compositions studied exhibit dielectric anomalies associated with structural phase transitions and their ferroelectric nature is corroborated by the presence of a sharp mixed mode (at ~190 cm-1) and by a Fano-type resonant dip in their Raman spectra.
|Research Institute, Centre or Group:||Materials and Engineering Research Institute > Structural Materials and Integrity Research Centre > Centre for Corrosion Technology|
|Depositing User:||Antonio Feteira|
|Date Deposited:||16 Sep 2016 14:27|
|Last Modified:||25 Oct 2016 21:23|
Actions (login required)
Downloads per month over past year