High-resolution absorption spectra of the chain compound Er 2BaNiO5 were measured in a wide range of frequencies (6000-20,000 cm-1) and temperatures (2.5-300 K). Energies of 38 crystal-field levels of Er3+ in a paramagnetic ...

A family of linear chain nickelates (ErxY1-x) 2BaNiO5 (x = 1, 0.8, 0.6, 0.4, 0.2, and 0.1) was studied by high-resolution spectroscopy of the Er3+ ion. Energies of 38 crystal-field levels of Er3+ and exchange splittings ...

Optical absorption spectra of the Yb2Ti2O7 single crystals and luminescence spectra of the Y2Ti 2O7:Yb (1%) polycrystalline samples were registered at temperatures 4.2-300 K. These spectra and earlier published data on ...