Magnetic properties of LaNi5 and their variation with hydrogen absorption and desorption

The hydrogen storage compound LaNi5 is an exchange-enhanced Pauli paramagnet with susceptibility chi (LaNi5)=4.6*10-6 EMU g-1. Hydrogen absorption leads to a decrease of the susceptibility of chi (LaNi5H6.0)=1.3*10-6 EMU g-1. This decrease is usually covered by a strong irreversible increase of surface magnetism, where, through surface segregation and decomposition, superparamagnetic Ni precipitations are formed. The two effects explain the controversial results about the magnetic properties of the LaNi5 hydride. The implication of this decomposition on the cyclic lifetime is discussed.

[1]  L. Schlapbach,et al.  Surface analysis of Mg2Ni?Mg, Mg2Ni and Mg2Cu? , 1980 .

[2]  L. Schlapbach,et al.  Magnetism and hydrogen storage in LaNi5, FeTi and Mg2Ni , 1980 .

[3]  K. Buschow,et al.  Hydrogen absorption and magnetic properties of intermetallic compounds based on 3d elements , 1980 .

[4]  D. Davidov,et al.  Electron-spin resonance of Gd in LaNi5single crystals: Resolved fine structure in hexagonal host and the role of random strains , 1979 .

[5]  L. Schlapbach,et al.  Catalytic effect in the hydrogenation of Mg and Mg compounds: Surface analysis of MgMg2Ni and Mg2Ni☆ , 1979 .

[6]  W. Göpel.  “Magnetic dead layers” on chemisorption at ferromagnetic surfaces☆ , 1979 .

[7]  H. Imamura,et al.  Mechanism of hydrogen absorption by lanthanum-nickel (LaNi5) , 1979 .

[8]  L. Schlapbach,et al.  A new mechanism for lengthening the lifetime of hydrogenation catalysts , 1979 .

[9]  H. Kronmüller,et al.  Magnetic aftereffect of hydrogen and deuterium in Co5Sm , 1979 .

[10]  L. H. Bennett,et al.  Nuclear magnetic resonance in LaNi5 , 1979 .

[11]  N. Kulikov.  Band structure and electronic properties of transition metal hydrides , 1979 .

[12]  L. Schlapbach,et al.  How FeTi Absorbs Hydrogen * , 1979 .

[13]  L. Schlapbach,et al.  Self restoring of the active surface in LaNi5 , 1979 .

[14]  T. V. Waldkirch,et al.  Surface segregation in LaNi5 induced by oxygen , 1978 .

[15]  L. Schlapbach,et al.  Self-restoring of the active surface in the hydrogen sponge LaNi/sub 5/ , 1978 .

[16]  J. Richardson.  Magnetism and catalysis , 1978 .

[17]  M. Campagna,et al.  Demagnetization of the Ni(100) Surface by Hydrogen Adsorption , 1977 .

[18]  D. Davidov,et al.  Mössbauer studies of 155Gd in LaNi5 and LaCo5 hydrides , 1977 .

[19]  D. Thome,et al.  Investigation of the systems LaNi5Hx and LaNi5Dx by proton and deuteron nuclear magnetic resonance , 1976 .

[20]  J. J. Burton,et al.  Surface segregation in alloys: Agreement between a quantitative model and experimental data for ethane hydrogenolysis over copper-nickel alloys , 1975 .

[21]  K. Buschow,et al.  Magnetic properties of LaCo5xNi5-5x , 1975 .

[22]  D. Davidov,et al.  STUDY OF DYNAMIC EFFECTS IN PARAMAGNETIC RESONANCE OF Gd IN LaNi$sub 5$ INTERMETALLIC COMPOUNDS. , 1968 .