New type-I clathrates with ordered Eu distribution
New type-I clathrates with ordered Eu distribution
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DOI：
10.1016/j.physb.2006.03.066
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发表时间：
2006-08-15
影响因子：
2.8
通讯作者：
Grin, Yu.
中科院分区：
文献类型：
--
作者：
Paschen, S.;Budnyk, S.;Grin, Yu.
在寻找含有稀土元素的包合物的过程中，我们发现了三个新的包合物-I相K6Eu2Ga10Ge36，K6Eu2Zn5Ge41和K6Eu2Cd5Ge41。Eu原子只占据较小的笼子(五角十二面体)，导致客体原子的完全有序排列。X射线吸收光谱和磁化率测量表明，在室温及以上，Eu在所有化合物中都接近二价。然而，低温下的磁化强度测量表明，K6Eu2Ga10Ge36和K6Eu2Zn5Ge41的磁矩略有降低。K6Eu2Ga10Ge36，K6Eu2Zn5Ge41和K6Eu2Cd5Ge41的铁磁有序温度分别为3.8，4.0和9.3K，而I类笼状化合物β-Eu8Ga16Ge30的铁磁有序温度为36K，其中所有笼子都被Eu占据。(C)2006爱思唯尔B.V.保留所有权利。
in our search for clathrates containing rare-earth elements we have discovered the three new clathrate-I phases K6Eu2Ga10Ge36, K6Eu2Zn5Ge41, and K6Eu2Cd5Ge41. The Eu atoms occupy only the smaller cages (pentagondodecahedra) leading to a fully ordered arrangement of the guest atoms. X-ray absorption spectroscopy and magnetic susceptibility measurements reveal that at room temperature and above Eu is close to divalent in all compounds. Magnetization measurements at low temperatures, however, may indicate slightly reduced magnetic moments for K6Eu2Ga10Ge36 and K6Eu2Zn5Ge41. The ferromagnetic ordering temperatures of 3.8, 4.0, and 9.3 K for K6Eu2Ga10Ge36, K6Eu2Zn5Ge41, and K6Eu2Cd5Ge41, respectively, are considerably reduced with respect to the 36 K observed for the type-I clathrate beta-Eu8Ga16Ge30 where all cages are occupied by Eu. (c) 2006 Elsevier B.V. All rights reserved.