Rare Earth Ion Pair Absorption at Low Concentrations in Lanthanum Trichloride

摘要

Fluorescence following the absorption of a single 32,000/cm photon by a pair of rare earth dopant ions has been observed at 4.2K. These samples were LaCl3 doped with 1%Ho(3+) or with 1%Pr(3+), and double doped with 1%Ho(3+) and 1%Pr(3+), and were known to contain trace amounts of Nd(3+). The fluorescence and excitation spectra indicated that in the Ho(3+) doped sample, the ion pair process Ho(quintent F(5)) + Nd(quadruplet G(5/2)) was absorbing at 32,000/cm. In the Pr(3+) doped sample, evidence was seen for the process Pr(singlet D(2))+ Nd(doublet H(11/2)) and for a weak pair process involving the Pr(3+) level triplet P(0) or one connected to it and either Pr(3+) or Nd(3+) levels. Other combinations of ion pairs which are energetically possible were searched for but not observed. (Author)