Engelbert Tuscher

Untersuchungen an Hydriden im Bereich der η-Phase Ti4Fe2O

Alloys of titanium and iron with varying oxygen content in the above mentioned phase take up considerable amounts of hydrogen. It will be shown, that hydriding and dehydriding can be processed in a reversible way. The hydrides have been investigated by X-ray, metallography, and NMR. Susceptibility and vapour pressure measurements have been performed The arrangement of the hydrogen atoms in the host lattice will be discussed.

Untersuchungen an Hydriden im Bereich der Phase Ti2CO1—xFex (x=0–0,5)

The hydrogen absorption of the phase Ti64Co32−xFex (x=0...16) and its influence on the magnetic properties have been investigated. Measurements of the vapour-pressure, wide-line NMR and magnetic susceptibility have been performed. Substitution of Co by Fe does not change the amount of absorbed hydrogen. However the reaction rate of hydriding process, the activation energy of diffusion and the magnetic quantities change upon this substitution.

Magnetische Eigenschaften von Hf2Fe und Hf2FeH x@@@Magnetic properties of Hf2Fe and Hf2FeH x (short communication): Kurze Mitteilung

The weakly temperature dependent paramagnetic compound Hf2Fe becomes ferromagnetic by hydrogen absorption, theCurie-temperature of the resulting hydrides depends on the hydrogen content.

Wasserstoffaufnahme und magnetisches Verhalten der intermetallischen Phasen Ti2(Ni,Co) und Ti2(Ni,Fe)

Hydrogen absorption by the intermetallic compounds Ti2(Ni,Co) and Ti2(Ni,Fe) with Ti2Ni-structure (Oh7-Fd3m) is accompanied by an increase of the volume of the unit cell without any structural change, while the maximum value of absorbed hydrogen is practically independent of the alloy composition. By taking up hydrogen, the intermetallic compounds, showingPauli spin paramagnetism with complex temperature dependence, become either temperature independent paramagnetic [hydrides of Ti2(Ni,Co)] or strongly temperature dependent paramagnetic, following a modifiedCurie-Weiss-Law [hydrides of Ti2(Ni,Fe)], respectively.

Magnetische Eigenschaften von η-Oxiden und η-Oxidhydriden der Dreistoffsysteme Ti-Co-O und Ti-Cu-O

Magnetic susceptibility measurements were performed on η-oxides of the systems Ti−Co−O and Ti−Cu−O, and the corresponding hydrides. In agreement with earlier investigations, it was found that the magnetic properties are strongly influenced by the amount of interstitial oxygen and hydrogen, respectively.

Dampfdruckmessungen und Protonenresonanzuntersuchung an Hydriden der intermetallischen Phasen Ti2(Ni, Co) und Ti2(Ni, Fe)

NMR and hydrogen equilibrium pressure measurements were performed on hydrides of the intermetallic compounds Ti2(Ni, Co) and Ti2(Ni, Fe). The following values of enthalpy ΔH and entropy ΔS for the formation of the hydrides of the intermetallic phases Ti2Co and Ti2Ni were found: ΔH(Ti2CoHy)=−47.6 kJ/mol H2, ΔH(Ti2NiHy)=−53.7 kJ/mol H2; ΔS(Ti2CoHy)=−119.8 J/(K·mol H2), ΔS(Ti2NiHy)=−127.5 J/(K·mol H2). By substitution of Ni or Co by Fe, the values of ΔH and ΔS of the corresponding quaternary hydrides become less negative. An interpretation of the experimental results is tried by the model ofShaltiel and coworkers.Proton diffusion was investigated in a series of the intermetallic hydrides Ti2(Ni, Co)Hx and Ti2(Ni, Fe)Hx. The diffusion rate is lowered by increased Ni/Fe substitution. Substitution of Ni by Co scarcely effects the “hopping process”. The activation energies were found to be smaller for the Ti2Ni-hydrides compared with the Ti2Co-hydrides.