Evidence for energy transfer between two distinct crystallographic europium sites in Eu(III) β″-alumina and between Eu(III) and Sm(III) in Co-doped β″-alumina

Abstract

The introduction of trivalent europium and samarium into β″-alumina yields materials in which energy transfer can be observed, either between europium ions in the Eu 3+-doped crystal or between samarium and europium in the Co-doped species. We have identified an acceptor site in europium by monitoring its 5D 0→ 7F 2 emission, where two of the europium crystallographic sites can be distinguished. In the europium-doped species, energy is preferentially accepted by the 608.1 nm component of a Beevers—Ross site at 300 K but not at 77 K. In the EuSm Co-doped species, samarium to europium transfer is observed at both 300 and 77 K.