Magnetism and Negative Magnetoresistance of Two Magnetically Ordering, Rare-Earth-Containing Zintl phases with a New Structure Type: EuGa2Pn2 (Pn = P, As)
Magnetism and Negative Magnetoresistance of Two Magnetically Ordering, Rare-Earth-Containing Zintl phases with a New Structure Type: EuGa2Pn2 (Pn = P, As)
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DOI：
10.1021/cm901219u
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发表时间：
2009-08
影响因子：
8.6
通讯作者：
A. Goforth;H. Hope;C. Condron;S. Kauzlarich;Newell Jensen;P. Klavins;S. Maquilon;Z. Fisk
中科院分区：
文献类型：
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作者：
A. Goforth;H. Hope;C. Condron;S. Kauzlarich;Newell Jensen;P. Klavins;S. Maquilon;Z. Fisk
EuGa2Pn2（Pn = P、As）单晶由熔融 Ga 助熔剂生长而成，并通过 100(1) K 下的单晶 X 射线衍射进行表征。它们是同构的，并以新的结构类型结晶（单斜晶系，P2/m，a = 9.2822(9) A，b = 3.8967(4) A，c = 12.0777(11) A, β = 95.5220(10)°, R1 = 0.0148, wR2 = 0.0325 (EuGa2P2) 且 a = 9.4953(7) A, b = 4.0294(3) A, c = 12.4237(9) A, β = 95.3040(10)°, R1 = 0.0155，wR2 = 0.0315（EuGa2As2））。该结构由二维 Ga2Pn2 阴离子和 Eu 阳离子的交替层组成。阴离子层由 Ga2Pn6 交错的类乙烷部分组成，具有罕见的 Ga−Ga 键合图案；这些部分通过共享的 Pn 原子以复杂的方式连接。两种结构都显示出较小的残余电子密度，可以通过添加一个 Eu 原子并去除两个键合的 Ga 原子来建模，从而得到大多数原子相同的结构 (<2%)，但键合方面存在差异，导致平行 Ga2Pn6 交错的一维带...
Single crystals of EuGa2Pn2 (Pn = P, As) were grown from a molten Ga flux and characterized by single-crystal X-ray diffraction at 100(1) K. They are isostructural and crystallize in a new structure type (monoclinic, P2/m, a = 9.2822(9) A, b = 3.8967(4) A, c = 12.0777(11) A, β = 95.5220(10)°, R1 = 0.0148, wR2 = 0.0325 (EuGa2P2) and a = 9.4953(7) A, b = 4.0294(3) A, c = 12.4237(9) A, β = 95.3040(10)°, R1 = 0.0155, wR2 = 0.0315 (EuGa2As2)). The structures consist of alternating layers of two-dimensional Ga2Pn2 anions and Eu cations. The anion layers are composed of Ga2Pn6 staggered, ethane-like moieties having a rare Ga−Ga bonding motif; these moieties are connected in a complex fashion by means of shared Pn atoms. Both structures show small residual electron densities that can be modeled by adding a Eu atom and removing two bonded Ga atoms, resulting in structures (<2%) where most of the atoms are the same, but there is a difference in bonding that leads to one-dimensional ribbons of parallel Ga2Pn6 stagge...