Discovered by E.A. Demarçay in 1901 in Paris, France. The most reactive member of the lanthanide group of elements and one of the less abundant (2.1 ppm in the Earth's crust), europium is a ductile silvery metal which reacts rapidly with air and water. As a result of its reactive nature, the metal has limited applications, but some is used in the manufacture of thin-film superconductor alloys. Europium is also used as control rod material in nuclear reactors due to its ability to absorb neutrons.Powder - Small particles with an approximately defined size range. Those materials described as alloy precursors are not true alloys - they are made by sintering a blend of powders of the component metals to achieve alloying by diffusion. The resultant cake is ground and sieved to the required particle size range. Unless otherwise stated, the particle sizes shown are for guidance only. We do not guarantee either any particular size distribution between the quoted minimum and maximum sizes, or a specific particle shape.