Positronium formation in lanthanide (III) trifluoroacetate with 3-picoline-N-oxide compounds.

Abstract

Positron annihilation lifetime and Doppler broadening annihilation radiation line shape on the salts Ln(CF3COO)3•xH2O and the adducts Ln(CF3COO)3(3-picNO)•xH2O (Ln=La–Pr, Sm–Lu and Y, and 3-picNO=3picoline-N-oxide, x in the range 0.75–1.33) were performed. Positroniumformation in the adducts, except for the europium complex, was observed. These results are discussed in terms of the electronic properties of the central metal ions.