Structural, optical and thermal studies of yttria/dysprosia nanocomposites; a suitable infrared transparent ceramic material

Abstract

Infrared transparent ceramic materials are specially fabricated materials, engineered to transmit the infrared rays which are meant to be used in heat seeking devices for missile guidance, night vision cameras, transparent armors and infrared inspection ports etc. The structural, optical and thermal properties of Yttria/Dysprosia (Y2O3/Dy2O3) nanocomposite sample at 80:20 mass ratio of yttria and dysprosia is presented in the paper. The nanocomposite powder is synthesized by an auto igniting modified combustion technique in a single step. The X-Ray diffraction (XRD) analysis reveals that the as prepared powder is composed of phases of bcc Y2O3 and Dy2O3 with an average crystallite size of 11.28 nm. The morphology of the sample is investigated by high-resolution transmission electron microscopy (HRTEM) coupled with selected area electron diffraction (SAED). The UV-Visible absorption spectrum is recorded in the range 200-800 nm and it shows maximum absorption in the UV region and decreases towards the visible region. The sample shows a band gap of 5.78 eV and a refractive index of 1.83. The theoretical transmittance of the well sintered pellet in the UV-Visible range is 84.15 %. Phase purity and vibrational mode of the sample is analyzed by FTIR spectroscopy. The thermal stability of the sample is confirmed by Thermo gravimetric analysis (TGA). Dysprosium is incorporated in yttrium matrix as a reinforcement agent and the properties on combination are studied. The properties exhibited by Y2O3/Dy2O3 nanocomposite powdered sample confirmed its suitability as ideal candidate for the fabrication of a high quality infrared transparent ceramic material.