Crystallization kinetics and structural properties of nanocrystalline europium-yttrium-titanate (Eu0.5Y0.5)2Ti2O7

Abstract

We present a versatile sol–gel approach for nanocrystalline (Eu0.5Y0.5)2Ti2O7. We determined the crystallization kinetics of the nucleation and the nucleation mechanism. The crystallization temperature was 1050.1 ± 0.8 K, and the activation energy of crystallization was 605 kJ mol−1. The nanocrystal growth started by homogenous nucleation with a constant nucleation rate, and the nanocrystal growth was limited by mass transfer through the phase boundary. The crystal structure of (Eu0.5Y0.5)2Ti2O7 was refined from the powder diffraction data using the Rietveld method, and the results were compared with the data recorded for the isostructural compounds, Eu2Ti2O7 and Y2Ti2O7. We proved the existence of a single phase of (Eu0.5Y0.5)2Ti2O7 and the regular distribution of Eu3+ and Y3+ ions inside the crystal lattice. The results provide key information regarding the crystallization properties and crystal structure of nanocrystalline (Eu0.5Y0.5)2Ti2O7. This knowledge is necessary for preparing pure nanocrystalline powders with tailored structural properties that are suitable for photonic applications. © 2022 The Society of Powder Technology Japan