Testing the Applicability of 119Sn Mössbauer Spectroscopy for the Internal Stress Study in Ternary and Co-Doped Ni-Mn-Sn Metamagnetic Alloys

The influence of both the Co addition and the internal stress on the atomic level magnetism is comparatively studied in Ni50Mn37Sn13 and Ni45Mn38Sn13Co4 alloys by magnetic measurements and 119Sn Mössbauer spectroscopy. The results show that the saturation magnetization and the hyperfine field follow the same temperature trend. The internal stress state is investigated by subjecting the samples to milling and annealing treatments, and tracking the singlet component revealed by 119Sn Mössbauer spectroscopy. Contrary to what was expected, in the Co-doped Ni-Mn-Sn sample the singlet component can be resolved between the milled and annealed states in both martensite and austenite phases. Therefore, the results demonstrate the feasibility of tracking the singlet component upon the structural recovery in Co-doped Ni-Mn-Sn alloys in a much wider range than in ternary alloys. In addition, it is concluded that the transferred dipolar field at Sn from the neighbor magnetic atoms depends very strongly on the stress field and on the microstructural order surrounding Sn atoms. The observed sensitivity of Sn Mössbauer probe atoms to slight microstructural distortions make 119Sn a powerful technique for the characterization of the stress present in Sn containing metamagnetic shape memory alloys.

Electrochemical lithiation/delithiation of SnP2O7 observed by in situ XRD and ex situ7Li/31P NMR, and 119Sn Mössbauer spectroscopy

The lithiation of the SnP2O7 anode material leads to tin extrusion and formation of LixSn alloys with stable capacity during the subsequent cycles.

119Sn Mössbauer spectroscopy of solvothermally synthesized fluorides ASnF3 (A = Na, K, Rb, Cs)

The complex Sn(II) fluorides ASnF3 (A = Na, K, Rb, Cs) were synthesized from the alkali fluorides and SnF2 in methanol through a solvothermal route. Their 119Sn Mössbauer spectra manifest divalent tin. The isomer shifts range from 3.09 to 2.94 mm s–1. The pronounced lone-pair character at the Sn(II) centres is expressed by strong electric quadrupole splitting (1.91–1.95 mm s–1). The two, respectively four crystallographically independent tin sites in NaSnF3, KSnF3 and RbSnF3 could not be resolved in the 119Sn spectra.