Tin Resonance Research Articles

Simple view of theMg2Si1−xSnxphonon spectrum: Sn resonances and mean field

We have studied the phonon spectrum of ${\text{Mg}}_{2}{\text{Si}}_{1\ensuremath{-}x}{\text{Sn}}_{x}$ alloys using both density-functional theory calculations and neutron measurements. In the low tin concentration limit a resonance is obtained in the lower part of the spectrum. At higher concentrations comparison between theory and experiments shows that a simple averaging of the force constants of the perfect crystals ${\text{Mg}}_{2}\text{Si}$ and ${\text{Mg}}_{2}\text{Sn}$ can explain the main features of the density of states. However we suggest that the tin resonance persists up to large tin concentrations and may therefore be important for transport properties.

Di- n-octyltin(IV) complexes with 5-[( E)-2-(aryl)-1-diazenyl]-2-hydroxybenzoic acid: Syntheses and assessment of solid state structures by 119Sn Mössbauer and X-ray diffraction and further insight into the solution structures using electrospray ionization MS, 119Sn NMR and variable temperature NMR spectroscopy

Reactions of 5-[( E)-2-(aryl)-1-diazenyl]-2-hydroxybenzoic acids (LHH′, where the aryl group is an R-substituted phenyl ring such that for L 1HH′: X = H; L 2HH′: X=2′-OCH 3; L 3HH′: X = 3′-CH 3; L 4HH′: X = 4′-CH 3; L 5HH′:X = 4′-Cl) with n Oct 2SnO in 2:1 and 1:1 molar ratios have been investigated. Two types of complexes, n Oct 2Sn(LH) 2 and {[ n Oct 2Sn(LH)] 2O} 2, were isolated and they have been characterized by 1H, 13C, 119Sn NMR, ESI-MS, IR and 119mSn Mössbauer spectroscopic techniques in combination with elemental analyses. The crystal structures of n Oct 2Sn(L 1H) 2 ( 1), {[ n Oct 2Sn(L 2H)] 2O} 2 ( 3) and {[ n Oct 2Sn(L 3H)] 2O} 2( 4) were determined. The mononuclear complex 1 was found to adopt a skew-trapezoidal bipyramidal arrangement around the tin atom while 3 and 4 are centrosymmetric tetranuclear bis(dicarboxylatotetrabutyldistannoxane) complexes containing a planar Sn 4O 2 core in which two μ 3-oxo O-atoms connect an Sn 2O 2 ring to two exocyclic Sn-atoms. The solution structures were confirmed by 119Sn NMR spectroscopy by observing one tin resonance in compound 1 and two tin resonances in {[ n Oct 2Sn(L 5H)] 2O} 2 ( 5). {[ n Oct 2Sn(L 2H)] 2O} 2 ( 3) and {[ n Oct 2Sn(L 3H)] 2O} 2 ( 4) undergo very complex exchange processes in deuteriochloroform solution, which has been confirmed by variable temperature 1H NMR spectroscopy. The cleavage of the most labile bond in the molecule was studied by ESI mass spectrometry.

155Gd and 119Sn Mössbauer effect investigations of GdCuSn and GdAuSn

155Gd and 119Sn Mössbauer effect measurements were performed on polycrystalline samples of GdCuSn and GdAuSn. The analysis of the gadolinium and tin resonance spectra allowed us to determine the directions of the gadolinium magnetic moments in the crystalline lattice as well as to draw conclusions about the magnetic structure of these materials. Measured quadrupole interaction constants at the gadolinium site give information about the axial coefficient B 0 2 of the crystalline electric field Hamiltonian.

Experimental verification of a simple method to avoid isotopic biases resulting from hyperfine structure in resonant ionization mass spectroscopy

Hyperfine structure plays a major role in producing “anomalous” odd-to-even isotope ratios in the stepwise excitation, ionization and mass analysis of an element with broad bandwidth, long-pulsed lasers. PAYNE et al. [ Spectrochim Acta 46B, 1439 (1992)] proposed that these anomalies may be avoided by cautious application of a simple prescription. We test the prediction by conducting a one-color, two-step ionization experiment on Sn at sufficient laser intensity such that the power-broadened width of a selected resonant transition exceeds the laser bandwidth. The laser is detuned from resonance by an amount greater than the laser bandwidth but less than the power-broadened width. The data obtained in our study confirm the prediction that a slightly detuned resonant ionization scheme effectively eliminates odd/even isotope ionization biases and that operating at adequate laser intensity produces a fairly wide detuning regime over which faithful odd/even isotope ratios are expected. Specifically, detunings of 5–10 cm −1 are sufficient to eliminate these biases in the two-photon stepwise (1 + 1) ionization by way of 3 P 0 → 3 P 1 resonance in tin (Sn) at a laser power density of 10 8 W cm −2.

Investigations of tin(II) halide aqueous solutions and solvent extracts by119Sn nuclear magnetic resonance spectroscopy: characterisation of the trihalogenostannate(II) anions [SnX3]–, [SnX2Y]–, and [SnX(Y)Z]–(X, Y, or Z = Cl, Br, or I)

The 119Sn chemical shifts of all ten trihalogenostannate(II) anions [SnClxBryIz]–(x+y+z= 3) are observed in diethyl ether extracts of tin(II) mixed-halide systems measured at –60°C. The tin(II) nuclear shielding order I < Br < Cl is the opposite of that found in tin(iv) halide systems. At room temperature, the tin resonance signals of tin(II) complexes in aqueous HCl, HBr, and Hl solutions, or their solvent extracts, are single peaks whose positions depend on the composition of the phase, showing that several species are in rapid equilibrium. The complex acids H [SnX3] exhibit 119Sn chemical shifts of δ=–40 (X = Cl), +135 (X = Br), and +350 (X = l) p.p.m. in ether extracts at room temperature.

57Fe- AND 119Sn-MÖSSBAUER SPECTROSCOPIC STUDIES OF THE MOLECULAR DYNAMICS OF (π-C5H5)Fe(CO)2Sn(C6H5)3 AND (π-C5H5)Fe(CO)2SnCl3

Abstract The Mössbauer effect of the 14.4 keV 57Fe and 23.8 keV 119Sn transitions has been studied in (π-C5H5)Fe(CO)2Sn(C6H5)3 and (π-C5H5)Fe(CO)2SnCl3 crystals. From the temperature dependence of the recoil-free fraction in iron and tin experiments, practically the same characteristic temperature (58 K for each Mössbauer resonance) has been found in the (π-C5H5)Fe(CO)2SnCl3, while two slightly different values (42 K for the iron resonance and 47 K for the tin resonance) have been estimated in the (π-C5H5)Fe(CO)2Sn(C6H5)3.

MÖSSBAUER STUDY OF LATTICE DYNAMICS OF HIGH Tc SUPERCONDUCTORS

Many strong-coupled superconductors have anomalous phonon properties. These anomalies manifest themselves as unusually soft modes, sometimes of a rather localized nature, or as anharmonic effects giving rise to hardening of certain modes at high temperatures. A study of lattice and electronic properties of high Tc Chevrel and P d ~ ~ s n ~ H superconductors has been made by means of the ll9Sn Mossbauer effect. In the high Te, high He2 superconductor SnM06Ss, the lattice is found to be anisotropic and anharmonic at the Sn site [I]. The degree of anharmonicity is large and obviates the use of perturbation treatments based on harmonic models. The results indicate that the phonon spectrum includes a strong tin resonance mode that hardens rapidly with increasing temperature. (Recent inelastic neutron scattering measurements are in agreement with this result [2]) . The impurity theory of Mannheim [3] has been applied to the results of our studies of the lattice dynamics of 1 lgSn in Pd. This study further corroborates the importance of nearest neighbor force constant changes and demonstrates the conditions for splitting a localized mode peak out of the host phonon spectrum. We have also studied the lattice dynamics of ll9Sn in the NaC1-type superconductor Pdo.99Sno.olH0,s. The addition of hydrogen has a marked effect on the electronic properties. We find a softening of the low energy tin modes and a hardening of the localized mode peak on hydriding. These results indicate softening of the Pd acoustic modes and the presence of a strong Sn-H interaction. (*) Based on work supported by the National Science Foundation and the U. S. Energy Research and Development Administration.

Radial Dependence of the Pseudodipolar Interaction in White Tin

The orientation dependence of the nuclear-magnetic-resonance linewidth in a single crystal of isotopically pure ${\mathrm{Sn}}^{119}$ has been interpreted in terms of the radial dependence of the pseudodipolar interaction. Lorentzian lines have been observed which are consistent with the existence of exchange narrowing and which, together with supplementary measurements of the second moment of the ${\mathrm{Sn}}^{119}$ resonance in tin of natural isotopic abundance, lead to an estimate of 11\ifmmode\pm\else\textpm\fi{}1 kHz for the strength of the scalar exchange interaction.

Azbel'-Kaner Resonance in Tin with Magnetic Field Perpendicular to the Surface

Azbel'-Kaner Resonance in Tin with Magnetic Field Perpendicular to the Surface

Cyclotron Resonance in Tin

Cyclotron Resonance in Tin

Cyclotron Resonance in Tin and Copper

Cyclotron Resonance in Tin and Copper