Chlorination of Pr2O3 and Pr6O11. Crystal Structure, magnetic and spectroscopic properties of Praseodymium Oxychloride.

FEDERICO J. POMIRO; JUAN PABLO GAVIRÍA; GASTÓN GALO GOUGA; LEORNARDO VEGA; BOHE, ANA ESTER

INORGANIC CHEMISTRY COMMUNICATIONS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2018 vol. 776 p. 919 - 926

1387-7003

The reactions of Pr2O3 and Pr6O11 with Cl2(g) were studied thermodynamically and experimentally, and proposed in the systems Pr2O3/Cl2(g) and Pr6O11/Cl2(g). A kinetic analysis was performed on Pr6O11 chlorination, which differs from with other light rare earth oxide chlorinations. The praseodymium oxychlorides obtained by full chlorination of Pr6O11 at 425 °C and 800 °C are different, being well characterized by X-ray diffraction, scanning electron microscopy, magnetic susceptibility measurements and X-ray photoelectron spectroscopy. The crystal structures of the oxychlorides were refined with the Rietveld method. The comparison between the theoretical m magnetic moment in the praseodymium oxychloride obtained at 425 °C revealed the presence of Pr3+ and Pr4+, whereas no significant difference was observed between the theoretical and the experimental values of Pr3+ obtained for the praseodymium oxychloride prepared at 800 °C. These observations are consistent with the analyses in the X-ray photoelectron spectra for both oxychlorides. Finally, a general formula of PrO1+xCl is proposed for the oxychlorides synthesized at T < 800 °C.