Ammonium Tungsten Bronze

Introduction

Ammonium tungsten bronze(ATB) is a kind of blue oxidation material with hexagonal or tetragonal structure which contains ammonium. If is more active than blue tungsten oxide, especially ammonium ion can interexchange with doping element—potassium. During reduction process, it will form tungsten phase structure with potassium which is helpful for potassium enters tungsten and disperse.

Preparation

1.Adding 0.01~1g organic tungsten source to dissolve in 20~40ml organic acid solution, and stir it.
2.Then adding 4~30ml organic ammonium, mix them up, remove to reaction still, hydrothermal crystallization for 0.5~48hours.
3.Contrifuge and wash the powder sample after reaction, and dry it under 40~250℃ vacuum circumstance for 1~12hours, the nano ammonium tungsten bronze particle is obtained.

By this method, hexagonal ammonium tungsten bronze can be obtained, its grain size can be adjusted between 80~500nm, of which the appearance is uniform, and has narrow particle size distribution. The chemical valance state exists as W6+ and W5+, full of free electron. Apart from that, ammonium tungsten bronze has strong absorbing infrared ray. Thin film contains nano particles can shield 780~2500nm of near infrared ray and can keep high transmittance.