Magnetic Properties of Ordered Perovskites Ba2MUO6 (M = Sc, Y, Gd, Yb, Mn)

✍ Scribed by Yukio Hinatsu

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 250 KB
• Volume: 105
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1993.1197

✦ Synopsis

Uranium complex oxides with the ordered perovskite structure (\mathrm{Ba}{2} M \cup \mathrm{OO}{6}(M=\mathrm{Sc}, \mathrm{Y}, \mathrm{Gd}, \mathrm{Yb}, \mathrm{Mn})) were prepared, and their magnetic susceptibilities and electron paramagnetic resonance (EPR) spectra were measured. The lattice parameter of the compounds varied linearly with the ionic radius of (M^{3+}). The effective magnetic moments of (\mathrm{U}^{5+}) in (\mathrm{Ba}{2} \mathrm{YUO}{6}) and (\mathrm{Ba}{2} \mathrm{ScUO}{6}) were very small. The moments of (\mathrm{Ba}{2} \mathrm{GdUO}{6}) and (\mathrm{Ba}{2} \mathrm{YbUO}{6}) were 7.74 and (4.69 \mu_{\mathrm{B}}), respectively, close to the theretical values for (\mathrm{Gd}^{3+}) and (\mathrm{Yb}^{3+}). The electron paramagnetic resonance spectrum was observed for (\mathrm{Ba}{2} \mathrm{GdUO}{6}). its (g)-value was 1.92. In (\mathrm{Ba}{2} \mathrm{MnUO}{6}), ferrimagnetic behavior was found below ca. (55 \mathrm{~K}). The effective magnetic moment was (5.52 \mu_{\mathrm{B}}) and the (g)-value of EPR was 2.00 . These results show that the manganese ion is divalent at a high spin state and that the uranium ion is in the hexavalent state. O 1993 Academic Press. Inc.