EPJ Web of Conferences (Jan 2016)

First ionization potential of the heaviest actinide lawrencium, element 103

  • Sato Tetsuya K.,
  • Asai Masato,
  • Borschevsky Anastasia,
  • Stora Thierry,
  • Sato Nozomi,
  • Kaneya Yusuke,
  • Tsukada Kazuaki,
  • Düllmann Christoph E.,
  • Eberhardt Klaus,
  • Eliav Ephraim,
  • Ichikawa Shinichi,
  • Kaldor Uzi,
  • Kratz Jens V.,
  • Miyashita Sunao,
  • Nagame Yuichiro,
  • Ooe Kazuhiro,
  • Osa Akihiko,
  • Renisch Dennis,
  • Runke Jörg,
  • Schädel Matthias,
  • Thörle-Pospiech Petra,
  • Toyoshima Atsushi,
  • Trautmann Norbert

DOI
https://doi.org/10.1051/epjconf/201613105001
Journal volume & issue
Vol. 131
p. 05001

Abstract

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The first ionization potential (IP1) of element 103, lawrencium (Lr), has been successfully determined for the first time by using a newly developed method based on a surface ionization process. The measured IP1 value is 4.9630.080.07 eV. This value is the smallest among those of actinide elements and is in excellent agreement with the value of 4.963(15) eV predicted by state-of-the-art relativistic calculations also performed in this work. Our results strongly support that the Lr atom has an electronic configuration of [Rn]7s25f147p11/2, which is influenced by strong relativistic effects. The present work provides a reliable benchmark for theoretical calculations and also opens the way for studies on atomic properties of heavy elements with atomic number Z > 100. Moreover, the present achievement has triggered a controversy on the position of lutetium (Lu) and Lr in the Periodic Table of Elements.