WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK.
J Phys Condens Matter. 2013 Feb 27;25(8):082202. doi: 10.1088/0953-8984/25/8/082202. Epub 2013 Jan 23.
We report here the synthesis of the site ordered double perovskite Ba(2)LuMoO(6). Rietveld refinement of room temperature powder x-ray diffraction measurements indicates that it crystallizes in the cubic space group Fm3m, with a = 8.3265(1) Å. Powder neutron diffraction data indicate that, unusually, this cubic symmetry is maintained down to 2 K, with [Formula: see text], Mo(5+) ions situated on the frustrated face-centred cubic lattice. Despite dc-susceptibility measurements showing Curie-Weiss behaviour with strong antiferromagnetic interactions at T ≥ 200 K, there is no evidence of long range magnetic ordering at 2 K. At T ≤ 50 K, susceptibility measurements indicate a loss in moment to ∼18% of the expected value, and there is a corresponding loss in the magnitude of the magnetic exchange. The structural and magnetic properties of this compound are compared with the related compound Ba(2)YMoO(6), which is a valence bond glass.
我们在这里报告了有序双钙钛矿 Ba(2)LuMoO(6)的合成。室温粉末 X 射线衍射测量的 Rietveld 精修表明，它在立方空间群 Fm3m 中结晶，a = 8.3265(1)Å。粉末中子衍射数据表明，不同寻常的是，这种立方对称性一直保持到 2 K，具有[Formula: see text]，Mo(5+)离子位于受挫的面心立方晶格上。尽管直流磁化率测量显示出居里-外斯行为，在 T ≥ 200 K 时具有强烈的反铁磁相互作用，但在 2 K 时没有长程磁有序的证据。在 T ≤ 50 K 时，磁化率测量表明磁矩损失到预期值的 18%左右，并且磁交换的幅度也相应减小。该化合物的结构和磁性性质与相关化合物 Ba(2)YMoO(6)进行了比较，后者是一种价键玻璃。
Zotero 插件