Magnetic and XPS studies of lithium lanthanide tetraphosphates LiLnP4O12 (Ln=Nd, Gd, Er)

Magnetic susceptibilities of flux-grown single crystals of LiLnP4O12 (Ln=Nd, Gd, Er) were measured in the temperature range of 2–300 K. The compounds were paramagnetic, and obeyed the Curie-Weiss law in the entire temperature interval, without magnetic phase transitions, and with effective magnetic moments close to those of the corresponding free Ln3+ ions. X-ray photoelectron spectroscopy was applied to determine the positions of core-level electrons relative to the Fermi level: Li 1s; Ln 4f, 5p, 5s, 4d, 3d; P 2s, 2p; O 1s, 2s. The binding energies in these compounds were found slightly shifted compared to the respective values of the same elements.