Variation the Crystalline Quality and The Band Gap Widening of Tellurium Doped Maghemite Thin Films Prepared by Pulsed Laser Deposition

Authors

  • A. S. Ahmed , Z.Y. Sulaiman ,A.A. Ramadhan

Abstract

Pulse laser deposition can be consider as a successful method to prepare metal oxide thin
films such as Fe2O3 with high degree of stoichiometric but with low degree of crystallinity
due to the bad temperature misfit between deposited material and the substrate temperature
which cause a high deviation between the standard and experimental value of lattice constant
, one of the method to treat this structural defect is the doping process, in this work the films
were prepared used pulse laser deposition , the pellet which consider as a source of the
mixed materials target was prepared by pressed two mixing high purity powder of Fe2O3
and TeO2 with different concentration (x=0.00, 0.03, 0.05, 0.1) wt.% , the structural and
optical properties of the thin films had been investigated using X-ray diffraction patterns and
UV-Visible spectrum . The X-Ray diffraction patterns revel that the structure was cubic and
the phase was maghemite. The Lattice constant and interplanar distance will stretch for pure
and doped films , the deviation from the standard value will take a positive value, this
distortion will increase with increase the doping concentration , for predominate plane (311)
the texture factor and the size will decrease with increase the doping concentration , the band
energy gap and the Urbach tail energy act as a blue and red respectively and this shifting act
for both of them in opsite direction that is the shift of energy gap decrease while the Urbach
energy increase with increase the doping concentration.

Published

2020-10-14

Issue

Section

Articles