Wydział Chemii

Małgorzata Puchalska

Adam Watras

2016

Journal of Alloys and Compounds

688

253-260

10.1016/j.jallcom.2016.06.291

Naukowa

Angielski

Artykuł

Two series of new calcium gallates: Ca_1−xNd_xGa₄O₇ and Ca_1−2xNd_xNa_xGa₄O₇(x = 0.001, 0.01, 0.03, 0.05, 0.1) were synthesized by a modified Pechini method and their optical properties at 298 K and 77 K were investigated. Relatively intense characteristic Nd³⁺ luminescence in IR region with maximum located at around 1075 nm was observed in all samples on direct excitation into f-f transitions. The effects of activator concentration and Na⁺ co-doping on morphology, luminescence and absorption spectra as well as decay kinetics were studied in details. The results show that both, the Nd³⁺ concentration and the alkali metal co-doping affected the optical properties but had no influence on the powders morphology. The studies of luminescence spectra (298 and 77 K) in a function of activator concentration showed an increasing distortion of the local symmetry of Nd³⁺ with raising activator content due to certain defects created in the crystal lattice. On the other hand co-doping with Na⁺ ions led to smaller disturbance of Nd³⁺ ions local symmetries and significantly enhanced luminescence. Analysis of decay kinetics of both series of compounds showed smaller concentration quenching in charge compensated with Na⁺ ions powders due to smaller clustering of Nd³⁺ ions in CaGa₄O₇lattice.

Calcium gallate, charge compensation, decay kinetics, Alkali metal co-doping

http://dx.doi.org/10.1016/j.jallcom.2016.06.291

http://www.elsevier.com