dysprosium (Dy)


Dysprosium. Image: ESPI.

Dysprosium is a silver-white metallic element of the lanthanide series. Discovered by P. E. Lecoq de Boisbaudran in Paris in 1886, its name comes from the Greek dysprositos meaning "hard to get". Its chief ores are monazite and bastnaesite. Its capacity to absorb neutrons makes it important in nuclear reactor control systems; dysprosium is also in making alloys for magnets and its compounds are used in lasers. Its most common isotope is 164Dy (28.18%).


atomic number 66
relative atomic mass 162.5
relative density 8.54
melting point 1,409°C (2,568°F)
boiling point 2,335°C (4,235°F)