Unusual superconductivity in crystallographically disordered RT2−xSn2 compounds
| العنوان: | Unusual superconductivity in crystallographically disordered RT2−xSn2 compounds |
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| المؤلفون: | Provino, Alessia, Smetana, Volodymyr, Shtender, Vitalii, Siebeneichler, Stefanie, Putti, Marina, Franz, Alexandra, Ferdeghini, Carlo, Pecharsky, Vitalij K., Mudring, Anja-Verena, Manfrinetti, Pietro |
| المصدر: | Journal of Alloys and Compounds. 1000 |
| مصطلحات موضوعية: | Rare-earth ternary intermetallics, RZn 2_x Sn 2 compounds, Crystal structure, Superconductivity, Electronic structure, Rare earth stannides |
| الوصف: | The discovery of new superconducting materials represents a complementary and crucial tile to shed light on the mechanism controlling the phenomenon of superconductivity. During the search for new superconducting materials, we discovered a new series of intermetallic compounds with the general composition RZn 2_x Sn 2 (R = La, Ce, Pr, Nd). Their formation and crystal structure have been investigated. The Zn content decreases along the series from approximate to 1.50 in LaZn 1.50(1) Sn 1.98(2) to approximate to 1.32 in NdZn 1.321(8) Sn 2.01(2) , due to the partial occupation of one of the two Zn sites [the Zn1 (2 c ) site, which from approximate to 50% in the La compound drops to approximate to 42%, approximate to 37% and approximate to 32% in the Ce, Pr and Nd compounds, respectively]. Both the Zn occupation factor and unit cell volume follow the lanthanide contraction. No such compound has been observed with Sm. AC and DC magnetic susceptibility and transport measurements revealed LaZn 1.5 Sn 2 to undergo a sharp superconducting transition at T c = 5.5 K. In order to search for further possible superconductive homologues, the lanthanum substituted phases La(Zn, T) 2 -x Sn 2 ( T = Ti, Mn, Fe, Co, Ni, Cu, Pd, Ag, Pt, Au, Cd; x approximate to 0.5) were also prepared. The crystal structure of the ternary compounds is a disordered defective derivative of the tetragonal CaBe 2 Ge 2 -type ( tP 10, P 4 /nmm ), with a partially occupied Zn Wyckoff site and a disordered Sn position. Three related isostructural series, corresponding to three new prototypes, have been identified; they all contain conventional checkered pyramidal layers characteristic of the archetype. The magnetic and transport properties have been measured for some of these substituted quaternary La compounds and we found that superconductivity is preserved in them but in the orthorhombic compounds or when T was a magnetic transition metal ( e.g. , Ni or Mn). A slight decrease in T c down to about 4.0 K was detected as a result of the Zn by T atomic substitution. |
| وصف الملف: | electronic |
| URL الوصول: | https://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-534810 https://doi.org/10.1016/j.jallcom.2024.175025 https://uu.diva-portal.org/smash/get/diva2:1883781/FULLTEXT01.pdf |
| قاعدة البيانات: | SwePub |
| تدمد: | 09258388 18734669 |
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| DOI: | 10.1016/j.jallcom.2024.175025 |