Intermetallic Compounds LaNi5 Research Articles

Ferromagnetic resonance in hydrogenated-dehydrogenated LaNi5, FeTi, and Mg2Ni and its relation to magnetic and surface investigations

The intermetallic compounds LaNi5, FeTi and Mg2Ni are Pauli paramagnets and therefore should not show any ferromagnetic resonance (FMR). Nevertheless FMR signals are observed in crushed samples and their intensity increases with the number of hydrogenation-dehydrogenation cycles. The FMR signal shows strong temperature dependence and for the pure Ni compounds it disappears just below the Curie temperature of pure Ni metal. The results are interpreted on the assumption that the FMR originates from superparamagnetic clusters that are formed by precipitating Ni or Fe atoms near the surface. The results are discussed in relation to previous magnetisation and surface measurements. Time-dependent behaviour observed at room temperature supports the superparamagnetic cluster picture, and is used to estimate the distribution of clusters on the surface. An additional narrower line with g=2.01+or-0.02 was observed at elevated temperatures and is attributed to magnetic resonance in the paramagnetic state.

Resistance of the intermetallic compound LaNi5 to attack by liquid and gaseous media

Resistance of the intermetallic compound LaNi5 to attack by liquid and gaseous media

Investigation of the Crystal Field in PrNi5

AbstractInelastic slow‐neutron scattering experiments are made on polycrystalline samples of intermetallic compounds PrNi5 and LaNi5 over the temperature range 8 to 295 K. The peaks of the inelastic magnetic‐neutron—rare‐earth‐ion scattering resulting from the splitting of the ion ground state into a number of levels by the crystal electric field (CEF) of hexagonal symmetry are identified by temperature and angular dependence of resonance intensities and by comparing PrNi5 spectra with those of LaNi5. On the basis of an effective point charge model for the CEF Hamiltonian with four variable parameters, calculations are made and CEF level scheme is restored. Magnetic contributions to the temperature dependence of heat capacity and magnetic susceptibility of PrNi5 are calculated and compared with available experimental data.

Electron spin resonance in LaNi5-Gd alloys-absence of dynamic effects in the bottleneck

The linewidth and g-shift as a function of temperature has been studied for various concentrations of Gd(4f7) in the intermetallic compound LaNi5. Both parameters show a strong temperature dependence which has previously been ascribed to dynamic effects in the electron spin resonance bottleneck. The authors show that this temperature dependence can be better explained by considering the effects of magnetic ordering in the compounds.