کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1412128 985786 2016 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Hydrogenation studies on NdScSi and NdScGe
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
Hydrogenation studies on NdScSi and NdScGe
چکیده انگلیسی


• Crystal structures of NdScSi and NdScGe were refined from single crystal XRD data.
• The hydrogenation of NdScSi leads to the formation of the NdScSiH1.5 hydride.
• NdScSiD1.5 adopts the La2Fe2Se2O3-type structure.
• Hydrogenation strongly reduces the ordering temperature of both intermetallics.

NdScSi and NdScGe were synthesized from the elements via arc-melting and subsequent annealing. Their ordered La2Sb type structures, with space group I4/mmm, were refined from single crystal X-ray diffractometer data: a=428.94(6) and b=1570.5(3) pm, wR2=0.0395, 309 F2 values for NdScSi and a=431.2(1) and c=1581.3(5) pm, wR2=0.1220, 227 F2 values for NdScGe, with 11 variables per refinement.Hydrogen insertion was performed on both Nd-based intermetallics by solid/gas reaction. Hydrogen uptake keeps the pristine compound space group but yields an anisotropic expansion of the unit cell with a large increase of c (≈+7%) and a slight decrease of a (≈−1.7%) parameters. Hydrogen absorption at 350 °C and under 5 bar of H2 pressure shows that the hydride NdScSiH1.48(5) is formed. An in-situ neutron diffraction study during the deuteration of NdScSi reveals for the first time in a CeScSi-type compound, the possibility to fill two interstitial sites with deuterium atoms, leading to the composition NdScSiD1.5 for the deuteride adopting then the La2Fe2Se2O3-type structure.From magnetization measurements, we evidence that hydrogenation strongly reduces the Curie temperature of NdScSi (TC=175 K) and NdScGe (TC=194 K) since NdScSiH1.5 and NdScGeHx undergo a magnetic transition at 4 K and around 2 K, respectively.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Solid State Chemistry - Volume 242, Part 2, October 2016, Pages 168–174
نویسندگان
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