NMR Studies of Structural Stabilization by Site-Selective Element Substitution in 1-2-20 System

Abstract

We report 119 Sn NMR studies on LaRu 2 Sn 2 Zn 18. LaRu 2 Sn 2 Zn 18 was synthesized by replacing a part of Zn of LaRu 2 Zn 20 with Sn. To clarify the substitution site of Sn in three batches of samples grown under different conditions, 119 Sn NMR spectra of the powder samples were measured. A significant difference in the NMR spectral shape and linewidth was observed depending on the growing conditions. We also measured the NMR spectrum of single-crystal and found that Sn was substituted only at the 16c site in the best sample. Besides, the analysis of the spectral shape considering the local symmetry around the Sn nucleus suggested the possibility of slight strain in the crystal, which might be due to the incomplete Sn substitution at the 16c site.