Structural evolution of Eu-doped hydroxyapatite nanorods monitored by photoluminescence emission

Luminescence variations in europium-doped silicon-substituted hydroxyapatite nanobiophosphor via three different methods

“…can be seen that the intensity of the PL increased with the sample prepared by the microwave and hydrothermal methods. It has been well documented that the coprecipitation method generally creates amorphous or less crystalline materials, whereas the microwave and hydrothermal techniques allow for the creation of a well-crystalline structure via higher temperature [23,27,35]. The increase in PL intensities should be mainly due to their different crystallinities, which was also consistent with the XRD results (Fig.…”

“…The homogeneous heating from the microwave or hydrothermal method can enhance the probability of nuclear growth and each facet of the nuclei has almost the same probability, resulting in weakly anisotropic growth; that is, the specimens have a low aspect ratio, as shown in Fig. 3(F) [26,27]. It is generally accepted that tailoring the morphology of HA-based materials often requires the use of surfactants (e.g.…”

Photoluminescence and doping mechanism of theranostic Eu3+/Fe3+dual-doped hydroxyapatite nanoparticles

“…The non-degenerate 5 D 0 →︀ 7 F 0 transition clearly indicates the presence of Eu 3+ in the host of HAp [49]. According to the literature, the ideal crystalline HAp has two different calcium sites: Ca(I) and Ca(II), and 5 D 0 →︀ 7 F 1 transition is related to Eu 3+ substitution in Ca(I) while 5 D 0 →︀ 7 F 2 transition is due to the substitution of Eu 3+ in Ca(II) [50]. Our results show that the peak from 603–640 nm has higher intensity than that from 570–603 nm, indicating that Eu 3+ ions have higher substitution percentage in Ca(II) sites than in Ca(I) sites of HAp host matrix.…”

Facile Synthesis, Characterization, and Cytotoxic Activity of Europium-Doped Nanohydroxyapatite

“…It is important to mention here that the hydrothermal treatment given to our nanoparticles gives them a well-defined size and morphology. André et al [21] obtained HA- and Eu-doped HA powders at room temperature and submitted them to the microwave hydrothermal method treatment (HTMW) at 140°C for 0, 1, 20, or 40 min and found a phase with hexagonal structure; they also verified that the HTMW treatment at 140°C at different times improves the crystallization process of the HA compared with samples obtained at room temperature. The use of the hydrothermal treatment to improve or to change the morphology of hydroxyapatite nanoparticles has also been reported by Xuan et al [22]; they changed a long nanowire morphology with length up to 500 nm and diameter less than 50 nm to a nanorod-like morphology.…”