Design of praseodymium-doped chalcogenide micro-disk emitting at 4.7 µm.

See more Praseodymium products. Praseodymium (atomic symbol: Pr, atomic number: 59) is a Block F, Group 3, Period 6 element with an atomic weight of 140.90765. The number of electrons in each of praseodymium's shells is 2, 8, 18, 21, 8, 2 and its electron configuration is [Xe]4f³ 6s². The praseodymium atom has a radius of 182 pm and a Van der Waals radius of 239 pm. Praseodymium resembles the typical trivalent rare earths, however, it will exhibit a +4 state when stabilized in a zirconia host. Unlike other rare-earth metals, which show antiferromagnetic and / or ferromagnetic ordering at low temperatures, praseodymium is paramagnetic at any temperature above 1 K. Praseodymium is found in the minerals monazite and bastnasite. Praseodymium was discovered by Carl Auer von Welsbach in 1885. The origin of the element name comes from the Greek words prasios didymos, meaning green twin.