ABSTRACT Non-stoichiometric oxynitride with a composition of EuTaO1.75N1.25 was synthesized in <10 min through urea route combined with modified pressureless spark plasma sintering apparatus. The electronic properties of EuTaO1.75N1.25 was investigated by first-principles calculations. X-ray powder diffraction revealed that EuTaO1.75N1.25 crystallized with the cubic perovskite-type structure, S.G. , and a lattice constant of a = 4.0283(7) Å. Thermogravimetric studies revealed that EuTaO1.75 N1.25 decomposed at around 345 under the oxygen atmosphere, giving a final product of decomposition as EuTaO4 and Eu5Ta4O15 oxides. Magnetic susceptibility measurements indicated EuTaO1.75 N1.25's paramagnetic behavior with an estimated T c =9.9 K. The saturation moment of 6.82 μB which is smaller than 7 μB expected for Eu2+ can be due to the existence of Eu3+. The extremely low value obtained for remanence and coercive field agrees to the isotropic character of the 8S7/2 ground state associated to the Eu2+.

中文翻译：

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非化学计量氮氧化物 EuTaO1.75N1.25 的快速合成、结构和磁性

摘要 通过尿素途径结合改进的无压放电等离子体烧结装置，在 <10 分钟内合成了组成为 EuTaO1.75N1.25 的非化学计量氮氧化物。通过第一性原理计算研究了 EuTaO1.75N1.25 的电子特性。X 射线粉末衍射显示 EuTaO1.75N1.25 结晶，具有立方钙钛矿型结构 SG 和 a = 4.0283(7) Å 的晶格常数。热重研究表明，EuTaO1.75 N1.25 在氧气氛下在 345 左右分解，得到分解的最终产物 EuTaO4 和 Eu5Ta4O15 氧化物。磁化率测量表明 EuTaO1.75 N1.25 的顺磁行为，估计 T c =9.9 K。饱和矩为 6。82 μB 小于 Eu2+ 预期的 7 μB 可能是由于 Eu3+ 的存在。剩磁和矫顽场获得的极低值符合与 Eu2+ 相关的 8S7/2 基态的各向同性特征。