Scaling behavior of the spin pumping effect in ferromagnet-platinum bilayers

We systematically measured the dc voltage V(ISH) induced by spin pumping together with the inverse spin Hall effect in ferromagnet-platinum bilayer films. In all our samples, comprising ferromagnetic 3d transition metals, Heusler compounds, ferrite spinel oxides, and magnetic semiconductors, V(ISH) invariably has the same polarity, and scales with the magnetization precession cone angle. These findings, together with the spin mixing conductance derived from the experimental data, quantitatively corroborate the present theoretical understanding of spin pumping in combination with the inverse spin Hall effect.     

Electron impact mass spectrometry of nuphar alkaloids. II—Thiohemiaminals

The appearance of m/e 228 and 176 ions, useful in ascertaining the presence of the hemiaminal hydroxyl, are discussed for six thiaspirane-type hemiaminals isolated from Nuphar luteum and three epimeric pairs of α-thiohemiaminals derived from (–)-deoxynupharidine. Other groups of ions useful in ascertaining stereochemical differences of the sulfur moiety in α-thiohemiaminals are discussed for the same compounds. One such group of ions is comprised of 248, 246 and 231; a second is 192 and 191.     

The solvent-induced shift in the proton NMR of some quinolizidine substituents

The proton chemical shift values for the methyl groups in the nine monomethylquinolizidines are determined in deuterochloroform and benzene solutions. This solvent change results in the shielding of all the methyl groups except those in 1(a)-and 3(a)-methylquinolizidine which become deshielded. These results are compared with those obtained earlier for equatoral and axial methyl and methylene groups attached to the quinolizidine systems in Nuphar alkaloids and related compounds.     

Electron-impact mass spectrometry of Nuphar alkaloids

Principal peaks in the mass spectra of deoxynupharidine are accounted for on the basis of high resolution mass spectrometry and peak shifts in the mass spectra of deoxynupharidine-4-d₁ and deoxynupharidine-6β, 7β-d₂. Cleavage of the quinolizidine ring system of deoxynupharidine occurs predominantly in ring A, giving m/e 136, 107, 98, 94 and 81. The origins of the family of ions [M — alkyl]⁺ and m/e 178 are considered. A comparative survey is made of the occurrence of these ions, and others, in the mass spectra of piperidine, quinolizidine and thiospirane types of Nuphar alkaloids. Attention is directed toions useful in distinguishing structural types.     

Local charge and spin currents in magnetothermal landscapes

A scannable laser beam is used to generate local thermal gradients in metallic (Co2FeAl) or insulating (Y3Fe5O12) ferromagnetic thin films. We study the resulting local charge and spin currents that arise due to the anomalous Nernst effect (ANE) and the spin Seebeck effect (SSE), respectively. In the local ANE experiments, we detect the voltage in the Co2FeAl thin film plane as a function of the laser-spot position and external magnetic field magnitude and orientation. The local SSE effect is detected in a similar fashion by exploiting the inverse spin Hall effect in a Pt layer deposited on top of the Y3Fe5O12. Our findings establish local thermal spin and charge current generation as well as spin caloritronic domain imaging.