Synthesis, crystal structure investigation and magnetism of the complex metal-rich boride series Crx(Rh1−yRuy)7−xB3 (x=0.88–1; y=0–1) with Th7Fe3-type structure
Synthesis, crystal structure investigation and magnetism of the complex metal-rich boride series Crx(Rh1−yRuy)7−xB3 (x=0.88–1; y=0–1) with Th7Fe3-type structure
复制标题
Th7Fe3型复杂富金属硼化物系列Crx(Rh1−yRuy)7−xB3 (x=0.88–1; y=0–1)的合成、晶体结构研究及磁性
DOI：
10.1016/j.jssc.2012.04.041
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发表时间：
2012
影响因子：
3.3
通讯作者：
B. Fokwa
中科院分区：
文献类型：
--
作者：
P. R. N. Misse;Mohammed Mbarki;B. Fokwa
在水冷铜坩埚中，在氩气保护下，通过电弧熔炼的方法，合成了新的复合硼化物系列Crx（Rh 1 −yRuy）7− xB 3（x=0.88-1; y=0-1）的粉末样品和单晶。产物具有金属光泽，其结构通过单晶和粉末X射线衍射以及EDX测量进行表征。在整个固溶体范围内，均为六方结构的Th 7 Fe 3（空间群P63 mc，no.186，Z=2）。单晶结构精修的结果表明，铬的存在下，在两个网站（6c和2b）的可用的三个金属维科夫网站，与一个明显的偏好为6c网站。一个意想不到的Rh/Ru网站的偏好被发现在富含Ru的区域，导致两种不同的磁性行为在固溶体中：Rh丰富的区域显示出温度无关的（泡利）顺磁性，而一个额外的温度依赖性顺磁性成分被发现在富含Ru的区域。
Powder samples and single crystals of the new complex boride series Crx(Rh1−yRuy)7−xB3(x=0.88–1; y=0–1) have been synthesized by arc-melting the elements under purified argon atmosphere on a water-cooled copper crucible. The products, which have metallic luster, were structurally characterized by single-crystal and powder X-ray diffraction as well as EDX measurements. Within the whole solid solution range the hexagonal Th7Fe3structure type (space group P63mc, no. 186, Z=2) was identified. Single-crystal structure refinement results indicate the presence of chromium at two sites (6c and 2b) of the available three metal Wyckoff sites, with a pronounced preference for the 6c site. An unexpected Rh/Ru site preference was found in the Ru-rich region only, leading to two different magnetic behaviors in the solid solution: The Rh-rich region shows a temperature-independent (Pauli) paramagnetism whereas an additional temperature-dependent paramagnetic component is found in the Ru-rich region.