Europium( <scp>III</scp> )‐Doped MgAl ₂ O ₄ Spinel Nanophosphor Prepared by <scp>CO</scp> ₂ Laser Co‐Vaporization

Abstract

Photoluminescent nanoparticles ( NP s) are of specific interest for biomedical applications, bioimaging, and cell tracking. Here, we report on the synthesis of europium( III )‐doped MgAl 2 O 4 spinel NP s by the CO 2 laser co‐vaporization of a homogeneous raw powder mixture consisting of micrometer‐sized MgAl 2 O 4 and Eu 2 O 3 (2 and 4 mol%, respectively). The resulting NP s are spherically shaped, show a narrow size distribution (mean diameter: ~30 nm), and are well dispersed. The as‐prepared NP s are highly crystalline and consist of MgAl 2 O 4 with small amounts of the secondary phases MgO (~10 mass%) and Eu 2 O 3 (&lt;0.5 mass%). The photoluminescence spectra of the doped spinel nanopowders show an intense red emission (λ em = 615 nm) resulting from the 5 D 0 → 7 F 2 transition with a maximum intensity at an excitation wavelength of 470 nm.