إتيربيوم (Yb)

الاكتشاف والتاريخ

تاريخ الاكتشاف: 1878 · Jean Charles Galissard de Marignac

In 1878, Ytterbium was discovered by the Swiss chemist Jean Charles Galissard de Marignac. While examining samples of gadolinite, Marignac found a new component in the earth then known as erbia, and he named it ytterbia, for Ytterby, the Swedish village near where he found the new component of erbium. Marignac suspected that ytterbia was a compound of a new element that he called "ytterbium". In 1907, the French chemist Georges Urbain separated Marignac's ytterbia into two components: neoytterbia and lutecia. Neoytterbia later became known as the element ytterbium, and lutecia became known as the element lutetium. The Austrian chemist Carl Auer von Welsbach independently isolated these elements from ytterbia at about the same time, but he called them aldebaranium (Ad; after Aldebaran) and cassiopeium. The American chemist Charles James also independently isolated these elements at about

الاستخدامات والتطبيقات

Ytterbium is found with other rare-earth elements in several rare minerals. It is most often recovered commercially from monazite sand (0.03 % ytterbium). The element is also found in euxenite and xenotime. The main mining areas are China, the United States, Brazil, India, Sri Lanka, and Australia. Reserves of ytterbium are estimated as one million tonnes. Ytterbium is normally difficult to separate from other rare earths, but ion-exchange and solvent extraction techniques developed in the mid- to late 20th century have simplified separation. Compounds of ytterbium are rare and have not yet been well characterized. The abundance of ytterbium in the Earth's crust is about 3 mg/kg. As an even-numbered lanthanide, in accordance with the Oddo–Harkins rule, ytterbium is significantly more abundant than its immediate neighbors, thulium and lutetium, which occur in the same concentrate at level

النظائر

Natural ytterbium is composed of seven stable isotopes: 168Yb, 170Yb, 171Yb, 172Yb, 173Yb, 174Yb, and 176Yb, with 174Yb being the most abundant (31.90 % natural abundance). Thirty-two synthetic radioisotopes have been observed, with the most stable being 169Yb with a half-life of 32.014 days, 175Yb with a half-life of 4.185 days, and 166Yb with a half-life of 56.7 hours. All of the remaining radioactive isotopes have half-lives that are less than 2 hours, with the majority of them being less than 20 minutes. This element also has 18 meta states, with the most stable being 169mYb (half-life 46 seconds). The known isotopes of ytterbium range from 149Yb to 187Yb. The primary decay mode for those isotopes lighter than the most abundant stable isotope, 174Yb, is electron capture giving thulium isotopes; the primary mode after is beta emission giving lutetium isotopes.