(INVITED) Reduced low temperature lifetimes of Bi3+ luminescence in magnetically ordered host lattices

This paper is specifically concerned with the radiative lifetime of the spin and orbitally forbidden Bi3+ 3P0 →1S0 emission transition. In diamagnetic host lattices, the lifetime of this strongly forbidden transition is long (∼1 ms). Experimental data in the literature show a drastic lifetime shortening in lattices containing Gd3+ compared to the diamagnetic lattices. Here, we propose that the lifetime shortenings have their origin in an internal magnetic field, the so-called molecular field, which is created at the Bi3+ site by the magnetically ordered Gd3+ sublattice. This molecular field mixes the 3P0 and 3P1 states to break the selection rule forbidding the 3P0 →1S0 emission transition.