Question

Write two applications of lanthanoids.

Answer 1

1. The lanthanoid compounds are present in every household. It is inside the colour television tubes. When electrons are bombarded on certain mixed lanthanoid compounds, they emit visible light over a small wavelength range. Therefore, the inside surface of a television tube or computer monitor is coated with tiny patches of three different lanthanoid compositions to give three colours that make the colour image.
   For example, a mixed oxide of europium and yttrium (Eu, Y)₂O₃ releases an intense red colour when bombarded with high energy electrons.
2. The optoelectronics applications use lanthanoid ions as active ions in luminescent materials. The most notable application is the Nd: YAG laser (Nd: YAG = neodymium-doped yttrium aluminium garnet).
3. Erbium-doped fibre amplifiers are significant devices in optical fibre communication systems.
4. Lanthanoids are used in hybrid cars, superconductors and permanent magnets.