Page 138 - Synthesis of Functional Nanoparticles Using an Atmospheric Pressure Microplasma Process - LiangLiang Lin

Chapter 7
Figure 7.2 Typical TG/DTG–DSC curves for the thermal decomposition of Y(OH)3:5%Eu3+ powders
lanthanide hydroxides to oxides after heat treatment is confirmed by the un-doped and 5%Eu-doped yttrium hydroxides and oxides show similar spectral characteristics, suggesting the Eu doping does not influence the absorption peaks. For the hydroxides samples, a broad band at 3602 cm-1 as well as a relatively narrow band at 1664 cm-1 are detected, which are assigned to the O-H vibration.10 The bands at 1510 cm-1, 1411 cm-1 and 1052 cm-1 are due to carbonyl groups, owing to the CO2 absorption from the ambient atmosphere.11 Meanwhile, the peaks at 819 cm-1 and 603 cm-1 are indexed to the Y-OH stretching mode.12 By contrast, for the spectra of the calcined samples, the intensities of OH and carbonyl bands decrease drastically. On the other hand, two new absorption bands relating to the Y(Eu)-O stretching mode appear at 555 cm-1 and
464 cm-1, indicating the forming of oxides.13
The dehydration of
infrared spectra (Figure 7.3). Both the
126