Structural, luminescence and magnetic properties of Yb3+-Er3+ codoped Gd2O3 hierarchical architectures

Abstract

In this paper, Gd(OH)₃ microcrystals (MCs), with hierarchical dumbbell-like structures, were prepared via a one-step hydrothermal route using KOH as the alkaline source and ethylenediaminetetraacetic acid as the chelating reagent. XRD patterns and SEM images showed the typical hexagonal phase and the three-dimensional micro-dumbbell structure with an average length of 9 μm and diameter of 7 μm. The time dependent morphogenesis, the growth kinetic mechanism and the intrinsic electric field were exploited to demonstrate the formation mechanism of the Gd(OH)₃ micro-dumbbell hierarchical architectures. Gd₂O₃ hierarchical MCs and their lanthanide-doped counterparts could also be obtained via heat treatment. Gd₂O₃:Yb³⁺/Er³⁺ hierarchical MCs exhibited relatively pure visible emission under near-infrared (980 nm) and violet (379.4 nm) excitation. Besides, NIR emission from Yb^{3+ 2}F_5/2 and Er^{3+ 4}I_13/2 was also found, which may be of particular interest for telecommunications applications. The possible energy transfer mechanisms were discussed. Moreover, Gd₂O₃ samples also have considerable magnetic mass susceptibility with a value of 1.321 × 10⁻⁴ emu g⁻¹ Oe⁻¹ by magnetic property studies. This work provides another path for preparing Gd₂O₃ hierarchical MCs.