Influence of high-energy ball milling on structural, microstructural, and optical properties of Mg2TiO4 nanoparticles

Abstract

In this paper, we report the impact of mechanical activation on structural, microstructural, thermal, and optical properties of Mg2TiO4 (MTO) nanoparticles prepared by high-energy ball milling. Williamson–Hall (W–H) method was carried out in order to understand the origin of the broadening in the X-ray diffraction (XRD) peaks and for the estimation of crystallite size of MTO nanocrystalline powder. It is revealed that the peak broadening is not only due to reduced coherently diffracting domain size but also due to a significant strain distribution. The calculated strain was 9.0 × 10−3 and the average crystallite sizes are 40–60 nm for 35-h milled powder and this result is consistent with transmission electron microscopy (TEM) analysis. To examine the nature of lattice fringes for the 35-h milled samples, high-resolution TEM study was carried out. It revealed that the as-prepared samples are highly crystalline in nature. The surface morphological studies were carried out by using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Further, MTO nanoparticles showed a strong absorption at ~ 356 nm, and the bandgap values ranged between 3.26 and 3.78 eV with an increase of milling time from 0 to 35 h. The photoluminescence (PL) spectrum measured at room temperature showed the bands which are belong to the near band edge emission at 357 nm. The MTO nanoparticles prepared by mechanical alloying method exhibited promising optical properties which are suitable for commercial optoelectronic applications.