Synthesis, characterisation and optical band gap of Cr_1.3Fe_0.7O₃ nanopigments

Abstract

Purpose

Inorganic pigments have been widely investigated due to their chemical stability such as resistance to chemical attacks by acids and alkalis, excellent hardness and high temperature stability. Cr_1.3Fe_0.7O₃ which is considered as a ceramic nanopigment also seems to be a highly efficient photovoltaic material. The paper aims to discuss these issues.

Design/methodology/approach

In this work, the paper reports the synthesis of a novel and high purity Cr_1.3Fe_0.7O₃ nanopigment via sol-gel process using stearic acid as complexing agent. The method includes formation of an organic precursor with metallic cations homogeneously distributed all over the matrix. Sample characterisations were performed by X-ray diffraction, electron microscopy, UV-vis diffused reflectance spectra and photoluminescence. The transport properties and colour characteristics were also investigated by spectroscopic and technological characterisation of the synthesised nanoparticles.

Findings

The prepared nanopigments were uniform in distribution and a spherical morphology with an average size of about 200 nm was observed. Cr_1.3Fe_0.7O₃ nanoparticles showed a direct band gap value of 2.85 eV and the colour efficiency of the nanopigments evaluated by colourimetric analysis resulted characteristic values of L*=39.96, a*=3.67 and b*=3.12.

Originality/value

This method for synthesis of nanopigments is novel and could be employed for various applications in synthesis of wide variety of nanoceramics.

Citation

Enhessari, M. (2013), "Synthesis, characterisation and optical band gap of Cr_1.3Fe_0.7O₃ nanopigments", Pigment & Resin Technology, Vol. 42 No. 6, pp. 347-352. https://doi.org/10.1108/PRT-09-2011-0079