Cooperative luminescence of ytterbium(III) in La2O3

Cooperative luminescence is reported for a dilute rare earth system, viz. La2O3Yb3+ 0.5 mol%. The observation of cooperative luminescence can be understood on the basis of the relatively strong interaction between the 4f electrons of neighbouring Yb3+ ions (in comparison to other rare earth ions) in a covalent host lattice such as La2O3.