Studies of anions from sputtering II: 99Tc and 99Ru

✍ Scribed by X.-L. Zhao; A.E. Litherland

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 480 KB
• Volume: 268
• Category: Article
• ISSN: 0168-583X
• DOI: 10.1016/j.nimb.2009.10.037

✦ Synopsis

A study of fluoride anion formation in PbF 2 matrices in a Cs + sputter source shows that, for transition metals Groups 3, 4 and 5, distinctively large currents (similar to PbF 3 À ) of their corresponding superhalogen anions [1] can be produced by Cs + sputter sources. This trend however, quickly breaks down for elements from Group 6 towards 12. The phenomenon can be understood as a competitive outcome of fluorination reactions among lead, caesium and transition metals, as their fluorine-binding energies generally decrease from Group 3 to 12. Therefore, if a strong fluorine-binding element, such as Mo, coexists with Ru in a fluorinated matrix, the formation of 99 RuF 4

À can be significantly suppressed relative to MoF 4 À and 99 TcF 4 À , a possible superhalogen anion of Tc. This phenomenon is indeed observed with a neutron irradiated Mo sample that contains trace levels of both 99 Tc and Ru, leading to a possible matrixassisted method for 99 Tc analysis using small and large accelerators.