Abstract

Crystals of a new intermetallic HT-Ce₂Rh₂Ga are grown by the high-temperature treatment of arc-melted alloys with stoichiometric composition. The compound crystallizes in the La₂Ni₃-type structure that is quite rare for intermetallics. The crystal structure of Ce₂Rh₂Ga is refined using two sets of ultrahigh-resolution X-ray diffraction data (sin θ/λ ≤ 1.356 Å⁻¹) obtained at 293 K: space group Cmce, Z = 4, a = 5.8646(7), b = 9.6388(7), and c = 7.4958(2) Å. The disordering of atoms near their averaged positions is found. The structure model is refined in the anharmonic approximation for the atomic displacements of all three atoms in the independent part of the unit cell to the values R₁/wR₂ = 1.36/1.17% and Δρ_min/Δρ_max = −0.56/0.41 e/ų for 1649 reflections constituting a cross data set obtained by averaging two independent data sets.

中文翻译：

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新型金属间Ce 2 Rh 2 Ga的晶体结构的细化

摘要

新型金属间化合物HT-Ce ₂ Rh ₂ Ga的晶体通过化学计量组成的电弧熔合合金的高温处理而生长。该化合物以La ₂ Ni ₃型结构结晶，这对于金属间化合物来说是非常罕见的。使用在293 K下获得的两组超高分辨率X射线衍射数据（sinθ/ λ≤1.356Å ^-1）精制Ce ₂ Rh ₂ Ga的晶体结构：空间群Cmce，Z = 4，a = 5.8646 （7），b = 9.6388（7）和c= 7.4958（2）Å。发现在其平均位置附近的原子无序。结构模型在非谐近似精制所有三个原子的原子位移在单元电池的独立部分，将值[R ₁ / WR ₂ = 1.36 / 1.17％和Δρ_分钟/Δρ_最大= -0.56 / 0.41 ë / A ³构成的横数据1649个反射集通过平均两个独立的数据集获得的。