Preparation of nanocrystalline lithium niobate powders at low temperature

Abstract

Key words lithium niobate powders, ammonium niobium oxalate, alternative solid-state method.A facile route to prepare lithium niobate (LiNbO 3 ) powders was proposed by an alternative solid-state method. Stoichiometric Li 2 C 2 O 4 and ammonium niobium oxalate were mixed with small amounts of water and then dried at room temperature. It was demonstrated that Li[NbO(C 2 O 4 ) 2 ]·nH 2 O intermediate was produced by an ion-exchange reaction. Pure LiNbO 3 powders were successfully synthesized by heating the intermediate at 500, 600 and 700 °C for 3 h. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, UV-Vis diffuse reflectance (UV-Vis) spectroscopy and thermogravimetric (TG) analysis were used to characterize the precursor compound and as-prepared samples. XRD results reveal that all the products are identified as hexagonal structure with high relative crystallinity (>87%). The particle size is found to be about 40 nm for the mixture calcined at 500 °C according to XRD data, which is in good agreement with SEM data. The as-prepared LiNbO 3 powders by this method are high quality according to FTIR spectra. (Li 0.996 Nb 0.005 )Nb 0.999 O 3 phase was formed when the calcination temperature was raised to 800 °C.

Mo2C catalyzed low-voltage prelithiation using nano-Li2C2O4 for high-energy lithium-ion batteries

“…6c verify the high air stability of the material. Three characteristic peaks at 764, 1318, and 1642 cm −1 belonging to Li 2 C 2 O 4 in the NLM materials exist in different resting states [29]. The TGA curve shows that the thermal decomposition temperature of Li 2 C 2 O 4 is as high as 450°C, and the introduction of the catalyst hardly weakens the thermal stability of Li 2 C 2 O 4 , thus showing excellent tolerance (Fig.…”

“…Fig. 4a displays the XRD patterns of the NLM lithium-compensation material before and [29]. Moreover, the Raman spectrum of the NLM prelithiation material in Fig.…”

Thermal, Magnetic and Electrical Properties of Multiferroic GdMnO3Nano Particles by a Co-Precipitation Method

“…In the temperature range of 400 • C-600 • C, DTA curve shows an endothermic and an exothermic peak at 448 • C, and 535 • C respectively. The endothermic at 448 • C corresponds to the combustion of intermediate oxalates and loss of carbonates and exothermic peak at 535 • C indicates the partial crystallization process is takes place [22]. The third weight loss occur between 600 and 800 • C and whose weight loss is equal to 0.52 mg (2.98%), due to the decomposition of all the oxalate materials.…”

Direct preparation of K0.5Na0.5NbO3 powders

“…However, most of the routes require high-purity raw materials, complicated procedures and specific apparatus. In this work, the synthesis and characterization of KNN powders are studied using ANO as Nb-source by an alternative solid-state method [30]. Its main advantage lies in the possibility of preparing accurate composition KNN powders at low temperature by a simple, rapid and low cost method, without the addition of any fuel.…”