Abstract We report on the structure and surface composition of Nd0.33Eu0.67Fe1-xCrxO3 (x = 0.0, 0.3, 0.5, 0.7, 0.9 and 1.0) nanoparticles (∼30 nm) mechanosynthesized at temperatures that are ∼ 470–700 °C lower than those at which the pure and doped pristine materials conventionally form. XRD Rietveld and FT-IR analyses show that with increasing x the lattice parameters decrease and the bond lengths and angles vary in a way that reduces crystalline distortion. Whilst the majority of the Eu3+/Nd3+ and Fe3+/Cr3+ cations occupy their normal perovskite-related A- and B-sites, respectively, ∼ 5 % of them exchange sites. 57Fe Mossbauer spectroscopy favours the presence of these antisites and reveals a superparamagnetic behaviour at 298 K that enhances with increasing x. XPS measurement reveals a complex surface composition of the nanoparticles with traces of Eu2O3, Nd2O3, Cr2O3 and Fe2O3 as well as partial O2−-deficiency.

中文翻译：

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机械合成纳米晶 Nd0.33Eu0.67Fe1-Cr O3 颗粒的结构、57Fe Mössbauer 和 XPS 研究

摘要 我们报告了 Nd0.33Eu0.67Fe1-xCrxO3 (x = 0.0, 0.3, 0.5, 0.7, 0.9 and 1.0) 纳米颗粒 (∼30 nm) 的结构和表面组成，该纳米颗粒 (∼30 nm) 在低于约 470–700 °C 的温度下机械合成与传统上形成纯和掺杂原始材料的那些相比。XRD Rietveld 和 FT-IR 分析表明，随着 x 的增加，晶格参数会降低，并且键长和角度会以减少结晶畸变的方式变化。虽然大多数 Eu3+/Nd3+ 和 Fe3+/Cr3+ 阳离子分别占据了与钙钛矿相关的正常 A 位和 B 位，但它们中的约 5% 交换了位点。57Fe Mossbauer 光谱有利于这些反位点的存在，并揭示了在 298 K 下的超顺磁性行为，随着 x 的增加而增强。