Size-controllable synthesis of lithium niobate nanocrystals using modified Pechini polymeric precursor method

Abstract

Nanopowders of lithium niobate (LiNbO 3 , LN) were synthesized by a water-based modified Pechini method, in which Li 2 CO 3 and ammonium niobate (v) oxalate hydrate (C 4 H 4 NNbO 9 ÁxH 2 O) are used as the Li and Nb source materials, respectively. The kinetics of formation of the intermediate gelatinous precursor was studied by thermal gravimetry and differential scanning calorimetry. The LN nanoparticles produced by calcining of the gel at various temperatures were characterized by X-ray diffraction and scanning electron microscopy. The effect of the calcination temperature on the morphology and structure of LN nanoparticles produced is investigated. The particle and crystallite sizes of the LN prepared could be controlled in the range of 20-250 nm by changing the calcination temperature of the gelatinous precursor.

One-pot synthesis of sub-10 nm LiNbO3nanocrystals exhibiting a tunable optical second harmonic response

“…The preparation of single-crystalline LiNbO 3 nanostructures, with well-dened dimensions and that exhibit minimal aggregation, is necessary for many of the targeted applications. [23][24][25][26][27] Many solid state approaches, molten salt syntheses, and sol-gel methods have been reported for preparing nanomaterials of LiNbO 3 . These methods have been limited in their ability to tune the size of the nanoparticles and to overcome aggregation in the products, and oen require high temperature treatment (>500 C) that result in the inclusion of micron sized particles.…”

“…These methods have been limited in their ability to tune the size of the nanoparticles and to overcome aggregation in the products, and oen require high temperature treatment (>500 C) that result in the inclusion of micron sized particles. 26,[28][29][30] In recent years, solution-phase approaches have attracted further attention to prepare nanomaterials with control over their shapes, sizes, and crystallinity, as well as to achieve minimal aggregation of these products. Solution-phase approaches include some relatively low temperature methods that are promising for the preparation of crystalline nanomaterials with dimensions below 100 nm.…”

Synthesis of Lithium Niobate Nanocrystals with Size Focusing through an Ostwald Ripening Process

“…This technique does, however, have limitations that include the need for high temperature calcination (~500 o C) and the formation of a relatively aggregated product. 36,37 Solution-phase methods have been sought to overcome many of these limitations.…”

Local Piezoelectric Behavior of Potassium Sodium Niobate Prepared by a Facile Synthesis via Water Soluble Precursors

“…[31][32][33] Recently, ammonium niobate (V) oxalate hydrate has been efficiently used as Nb-source in different complex forms through the chemical chelation in water for enhancing its gel formation capability. [34,35] The most promising candidate as chelating agent is represented by the citric acid. It is a polydentate ligand with a hydroxylic functional and three carboxylic groups and, among its several benefits, it allows to easily form soluble and stable chelating complexes with metal cations in an acidic or alkalescent solution.…”

“…On the other hand, the many steps involved in the preparation process with niobium oxide reagent, are time consuming and imply drawbacks for the use of hydrofluoric acid (HF) in order to prepare niobic acid or at high temperature . Recently, ammonium niobate (V) oxalate hydrate has been efficiently used as Nb‐source in different complex forms through the chemical chelation in water for enhancing its gel formation capability . The most promising candidate as chelating agent is represented by the citric acid.…”