Nuclear quadrupole interaction of 243Am3+ in LaCl3 measured via optical spectral-hole burning.

Abstract

An optical spectral-hole burning technique has been used to study the nuclear quadrupole splitting in the ground state of $^{243}\mathrm{Am}^{3+}$ in ${\mathrm{LaCl}}_{3}$. The observed splitting is consistent with ${\mathrm{Am}}^{3+}$ ions on an axially symmetric site. The nuclear quadrupole coupling constant P=-75\ifmmode\pm\else\textpm\fi{}1 MHz for the $^{7}$${\mathit{F}}_{0}$ ground state is obtained based on an effective operator Hamiltonian. The crystal-field antishielding effect dominates whereas contributions from the 5f electrons and from the pseudoquadrupole interaction are negligible (${\mathit{P}}_{5\mathit{f}}$/${\mathit{P}}_{\mathrm{latt}}$=0.03). The Sternheimer antishielding factor, ${\ensuremath{\gamma}}_{\mathrm{\ensuremath{\infty}}}$=-154, is determined and comparison is made between the actinide ion ${\mathrm{Am}}^{3+}$ and its rare-earth analogy ${\mathrm{Eu}}^{3+}$. \textcopyright{} 1996 The American Physical Society.