27Al and 45Sc NMR Spectroscopy on ScT2Al and Sc(T0.5T′0.5)2Al (T = T′ = Ni, Pd, Pt, Cu, Ag, Au) Heusler Phases and Superconductivity in Sc(Pd0.5Au0.5)2Al12. Issue 2 (27th January 2015)

• Record Type: Journal Article
• Authors: Benndorf, Christopher; Niehaus, Oliver; Eckert, Hellmut; Janka, Oliver
• Is Part Of: Zeitschrift für anorganische und allgemeine Chemie. Volume 641:Issue 2(2015)
• Page Start: 168
• Page End: 175
• Publication Date: 2015-01-27
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry -- Periodicals; 540
• DOI: 10.1002/zaac.201400509
• Languages: English
• ISSNs: 0044-2313

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The intermetallic <italic>Heusler</italic> compounds with Sc<italic>T</italic><sub>2</sub>Al and Sc(<italic>T</italic><sub>0.5</sub><italic>T′</italic><sub>0.5</sub>)<sub>2</sub>Al composition with <italic>T</italic> = <italic>T'</italic> = Ni, Pd, Pt, Cu, Ag, Au were synthesized from the elements by arc melting. They crystallize in the cubic MnCu<sub>2</sub>Al type structure, space group <italic>Fm</italic><inline-formula><alternatives><tex-math notation="tex"><![CDATA[$\bar{3}$]]></tex-math><inline-graphic xlink:href="ark:/27927/pgh3xswfb4d" mimetype="image" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /></alternatives></inline-formula><italic>m</italic>. The unit cell parameters were determined by powder X‐ray diffraction and the structure of Sc(Pd<sub>0.5</sub>Au<sub>0.5</sub>)<sub>2</sub>Al was refined on the basis of single‐crystal X‐ray diffraction. While the majority of the compounds show Pauli‐paramagnetism, ScAu<sub>2</sub>Al and the newly synthesized solid solution Sc(Pd<sub>0.5</sub>Au<sub>0.5</sub>)<sub>2</sub>Al exhibit superconductivity with transition temperatures of <italic>T</italic><sub>C</sub> = 4.4 K and <italic>T</italic><sub>C</sub> = 3.0(1) K, respectively. The superconducting state of Sc(Pd<sub>0.5</sub>Au<sub>0.5</sub>)<sub>2</sub>Al was also investigated by electrical resistivity measurements. All the synthesized compounds were furthermore studied by <sup>27</sup>Al and <sup>45</sup>Sc MAS‐NMR spectroscopy. The resonance shifts of the synthesized compounds were determined and in Sc(Pd<sub>1–<italic>x</italic></sub>Au<italic><sub>x</sub></italic>)<sub>2</sub>Al a linear relationship between the resonance shifts and the composition was found. Line broadening effects and enhanced quadrupolar interaction strengths observed in the mixed samples can be attributed to the effect of Pd/Au mixing on the 8<italic>c</italic> Wyckoff site. The NMR spectroscopic data give no clear evidence for or against Sc/Al site disordering.</p> </abstract>