Preparation and magnetic and microwave absorption properties of MnNb₂O₆ ellipsoid-like hierarchical structures

Abstract

The MnNb2O6 ellipsoidal hierarchical structures exhibiting antiferromagnetic behavior with TN ≈ 4 K are fabricated using a facile hydrothermal method.

Emerging cool white light emission from Dy3+ doped single phase alkaline earth niobate phosphors for indoor lighting applications

“…and they mostly exist in an isostructural form of orthorhombic structure with a columbite mineral group with the exception of the M = Sr, Ba and Pb analogues, which crystallize in different orthorhombic structures. [15][16][17] In this quest, barium metaniobate (BaNb 2 O 6 ) has been selected as a host lattice due to its smaller band gap and exhibits higher charge generation under UV light irradiation compared to other binary niobates. Moreover, BaNb 2 O 6 has been widely used as a high quality refractory material for photocatalytic and microwave dielectric applications in recent years.…”

Reduction of Transition-Metal Columbite-Tantalite as a Highly Efficient Electrocatalyst for Water Splitting

“…29,32 Second, the liquid−liquid extraction was carried out with 10 mL of the filtered solution added to 10 mL MIBK and maintained at 25 °C for 15 min to form the organometallic complex. 61,62 The solution was separated using a separation funnel; 20 mL of the organo-metallic solution was then transferred back into a 50 mL conical tube and a 25% ammonia solution of equal volume (V aq /V org ) was added to allow the metal hydroxide separation. The white precipitate was allowed to settle for 1 h and then centrifuged at 7000 rpm for 10 min.…”

Extraction of non-noble metal columbite-tantalite as a highly efficient electrocatalyst for water splitting

“…The synthetic columbite-tantalite AB2O6 (A = Fe, Mn, and B = Nb, Ta) was prepared by a hydrothermal method, followed by calcination 59,60 . First, 0.2 mmol ammonium niobate(V) oxalate hydrate was dissolved in distilled water and 0.2 mmol tantalum chloride precursor was dissolved in a concentrated methanol solution for 5 min.…”

“…First, the digestion of the coltan ore was placed in a polypropylene beaker with 8 M HF and stirred at room temperature for 3 h, followed by adding 8 M HCL and stirring the mixture at 80°C for 8 h. Then, the dissolved metals was filtrated 29,33,57 . Secondly, the liquid-liquid extraction was carried out with 10 mL of filtrated solution added to 10 mL methyl isobutyl ketone (MIBK) and maintained at 25°C for 15 min to form the organo-metallic complex [58][59][60] . The solution was separated using a separation funnel.…”