Hydrothermal synthesis, characterization and Raman studies of Eu3+ activated Gd2O3 nanorods

Abstract

a b s t r a c tEu 3 + (8 mol%) activated gadolinium oxide nanorods have been prepared by hydrothermal method without and with surfactant, cityl trimethyl ammonium bromide (CTAB). Powder X-ray diffraction (PXRD) studies reveal that the as-formed product is in hexagonal Gd(OH) 3 :Eu phase and subsequent heat treatment at 350 and 600 1C transforms the sample to monoclinic GdOOH:Eu and cubic Gd 2 O 3 :Eu phases, respectively. The structural data and refinement parameters for cubic Gd 2 O 3 :Eu nanorods were calculated by the Rietveld refinement. SEM and TEM micrographs show that as-obtained Gd(OH) 3 :Eu consists of uniform nanorods in high yield with uniform diameters of about 15 nm and lengths of about 50-150 nm. The temperature dependent morphological evolution of Gd 2 O 3 :Eu without and with CTAB surfactant was studied. FTIR studies reveal that CTAB surfactant plays an important role in converting cubic Gd 2 O 3 :Eu to hexagonal Gd(OH) 3 :Eu. The strong and intense Raman peak at 489 cm À 1 has been assigned to A g mode, which is attributed to the hexagonal phase of Gd 2 O 3 . The peak at $ 360 cm À 1 has been assigned to the combination of F g and E g modes, which is mainly attributed to the cubic Gd 2 O 3 phase. The shift in frequency and broadening of the Raman modes have been attributed to the decrease in crystallite dimension to the nanometer scale as a result of phonon confinement.

Novel Gd(OH)3, GdOOH and Gd2O3 Nanorods: Microwave-Assisted Hydrothermal Synthesis and Optical Properties

“…This kind of interaction is directly related to the water capacity for electromagnetic radiation absorption and efficiency in converting electromagnetic radiation to thermal energy [25][26][27][28] . Therefore, the reaction time and temperature necessary for obtaining of such materials in this work is significantly lower than those described in the literature [29][30][31][32] providing a significant improvement on crystallinity and morphology.…”

Synthesis, growth and photoluminescence behaviour of Gd2O2SO4:Eu3+nanophosphors: the effect of temperature on the structural, morphological and optical properties

“…In addition, the elemental analysis was obtained by EDAX analysis, shown in Figure 3c, which clearly demonstrates a homogeneous distribution of gadolinium, carbon, oxygen, and sulphur elements. 27,28 The weaker absorption band located at 240 nm was due to the transition from the 2p orbitals of O 2to the 4f orbitals Gd 3+ ion, the band ascribed to the absorption of Gd 2 O 2 SO 4 host crystal. In agreement with the FE-SEM results, the average breadth in the middle part of needles was measured in the range of 50-55 nm.…”

Spherical and rod-like Gd 2 O 3 :Eu 3 + nanophosphors—Structural and luminescent properties

“…C, cubic phase; M, monoclinic phase; H, hexagonal phase; * reported in Dhananjaya et al (2010Dhananjaya et al ( , 2011b. for 3 h, the agglomeration was reduced with increase in grain growth ( figure 3 (b)).…”