Evidence of reaction intermediates in microwave-assisted synthesis of SHG active α-La(IO₃)₃nanocrystals

Abstract

Highlighting the lanthanum iodates compounds and phase transformations through microwave-assisted hydrothermal syntheses.

Luminescent Yb3+,Er3+-Doped α-La(IO3)3 Nanocrystals for Neuronal Network Bio-Imaging and Nanothermometry

“…Yb 3+ ,Er 3+ -doped α-La(IO 3 ) 3 nanocrystals (with doping concentrations of 0.5 mol% Er 3+ and 10 mol% Yb 3+ ) were prepared by a microwave-assisted hydrothermal method as reported in [ 35 ]. The obtained nanocrystals, imaged by low-temperature transmission electron microscopy (TEM, Figure 1 a), present an average size of 40 nm and a good polydispersity (±10 nm), obtained by the size analysis on more than one hundred nanocrystals.…”

“…Both solutions were mixed together and poured into a quartz vessel, then placed into an Anton-Paar Multiwave PRO microwave oven (Anton-Paar, Graz, Austria). The heating was conducted at 250 °C for 10 min to crystallize the α-La(IO 3 ) 3 phase [ 35 ]. After cooling down, the white precipitate is retrieved by filtering and washed several times with distilled water before drying at room temperature for 24 h.…”

“…Yb 3+ ,Er 3+ -doped α-La(IO 3 ) 3 nanocrystals were recently developed with the goal of proposing multi-functional nanoprobes for in vitro imaging. The key advantage of these nanocrystals lies in their dual emission properties [ 32 , 33 ]: (1) As non-centrosymetric nanostructures, non-linear optical signals, such as the second harmonic, can be generated upon near-infrared femto-second excitation [ 34 ]; and (2) the facile, thus efficient, substitution of La 3+ by Er 3+ and Yb 3+ ions leads to PL properties in the visible and near-infrared range [ 35 ]. Such a combination paves the way to bio-imaging using multiple and complementary imaging techniques: Fluorescence imaging using a conventional epifluorescent microscope and in-depth imaging using a two-photon microscope equipped with a short-pulse excitation laser.…”

Solution‐Based Synthesis Routes for the Preparation of Noncentrosymmetric 0‐D Oxide Nanocrystals with Perovskite and Nonperovskite Structures

“…Impact of small changes in the experimental parameters was also clearly evidenced for the synthesis of α‐La(IO 3 ) 3 after simple coprecipitation in water between LaCl 3 and HIO 3 and heat‐treatment for a few minutes around 220 °C of the amorphous intermediate. [ 232 ] The subtle interplay between the synthesis temperature, radiation power, precursor concentration already discussed in ref. [233] and molar ratios between La 3+ and IO 3 − ions is summarized below ( Figure a).…”

“…b) Illustration of the reaction scheme and phase transformations according to the experimental conditions. Adapted with permission [232]. Copyright 2020, the Royal Society of Chemistry.…”