A systematic investigation of structural, magnetic and transport properties of NiCr_1.9R_0.1O₄ (R = Eu, Dy and Ho) has been undertaken. Rietveld analysis of powder X-ray diffraction data revealed that all the compounds crystallize in the cubic symmetry with Fdm space group having small volume fraction of orthorhombic phase RCrO₃. Both lattice parameter and cell volume decreases with the substitution of heavier rare earth ion which is consistent with the decrease in ionic radius of rare earth ion. The temperature dependent magnetization studies have shown that all our investigated compounds have negative value of Weiss constant. It indicates the dominance of anti-ferromagnetic interactions in the samples. The phases are semi-conductors and the conduction mechanism is dominated by Arrhenius model in the high temperature paramagnetic semiconducting region.

中文翻译：

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稀土掺杂亚铬酸镍的合成，结构和物理性能

已经对NiCr _1.9 R _0.1 O ₄（R = Eu，Dy和Ho）的结构，磁性和传输性能进行了系统研究。粉末X射线衍射数据的Rietveld分析表明，所有化合物均以立方对称的形式结晶，且Fd m空间群的正交晶相RCrO _3的体积分数小。。晶格参数和晶胞体积均随重稀土离子的取代而降低，这与稀土离子离子半径的减小相一致。温度相关的磁化研究表明，我们研究的所有化合物的Weiss常数均为负值。它表明了样品中反铁磁相互作用的优势。相是半导体，并且在高温顺磁半导体区域中，导电机理由Arrhenius模型控制。