Measurement of quantum yield of up-conversion Luminescence in Er(3+)-doped nano-glass-ceramics.

A measurement of quantum yield of up-conversion luminescence has been done for the Er(3+)-doped transparent oxyfluoride glass-ceramics 32(SiO,)9(AlO1.5)31.5(CdF2)18.5(PbF2)5.5(ZnF2): 3.5(ErF3) mol%, where most of Er3+ dopants partition in 8 nm diameter nano-crystals Er10Pb25F65. The yield was found by newly proposed method using the pump power dependence of the resonant luminescence. The result of the measurement points out that a theoretical maximum of 50% may be reached for the up-conversion luminescence yield in this material. This high yield is shown to be due to low phonon energy and short inter-dopant distances in the nano-crystals.

Preparation and up-conversion luminescence of 8 nm rare-earth doped fluoride nanoparticles.

Free-standing, 8 nm diameter, rare-earth doped nanoparticles Re(10)Pb(25)F(65) have been prepared, where Re stands for either single rare-earth ion, such as Er(3+), Yb(3+), Eu(3+), Dy(3+), Ho(3+), Tm(3+) or combinations of those ions. The nanoparticles have been extracted by chemical etching from the oxyfluoride nano-glass-ceramics template and analyzed by transmission electron microscope with energy dispersion spectroscopy. The nanoparticles show durable up-conversion photoluminescence, which is neither concentration nor impurity quenched after 6 months ageing in ambient atmosphere. High doping levels in these nanoparticles ensure high, up to 15%, quantum yield of up-conversion luminescence.

Broadband telecommunication wavelength emission in Yb(3+)-Er(3+)-Tm(3+) co-doped nano-glassceramics.

Transparent Yb(3+), Er(3+) and Tm(3+) co-doped nano-glass-ceramics 3(SiO(2)2)9(AlO(1.5))31.5(CdF(2))18.5(PbF(2))5.5(ZnF(2)):3.5(Yb-Er-TmF(3)), mol%, have been prepared where co-dopants mostly partition in nano-crystals Pb(1-x) (Yb(3+),Er(3+),Tm(3+))(x)F(2+x) embedded in the glass network. The Yb(3+) ensures high absorption at 980 nm telecommunication pump wavelength and further phonon-mediated energy transfer to Er(3+) and Tm(3+) co-dopants. Er(3+) and Tm(3+) radiate overlapping emission bands from their lowest energy levels, with similar lifetime of about 9 ms, which cover the range between 1.50 to 1.70 mum. The lifetime of all higher levels of Er(3+) and Tm(3+) dopants is shorter than 70 mus due to short inter-dopant distances in the nano-crystals resulting in fast energy transfer to their lowest levels.

Probing the magnetic anisotropy of lanthanide-containing metallomesogens by luminescence spectroscopy.

The alignment of liquid crystals through magnetism demands a high value of the magnetic anisotropy. The magnitude of the anisotropy for a series of isostructural lanthanide-containing metallomesogens can be estimated on basis of the crystal-field splitting of the (7)F1 multiplet in the corresponding europium(III) compounds. A method to rapidly measure this splitting value is accessible through photoluminescence measurements.

Absolute configuration assignment of D3-symmetric lanthanide complexes based on circular dichroism induced by interaction with a chiral probe.

Chiroptical properties and absolute configuration have been correlated for a series of [Ln(oda)3](3-) complexes in aqueous solution (Ln=Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, or Tm; oda=2,2'-oxydiacetic acid). Addition of the chiral probe L-proline (L-Pro) to a series of the racemic complexes resulted in an excess of the Λ-enantiomer.