Chapter 6 Magnetism of hydrides

Effect of hydrogen on magnetic properties of Lu2Fe14B single crystal

“…The hydrogen absorption causes a ∼6% increase in the spontaneous magnetization σ s and, consequently, in M Fe (see Table 1). This is a general feature of hydrides of the R-Fe intermetallics, which is caused by the narrowing 3d band upon the volume expansion [2,3]. The magnetic anisotropy energy E a = K 1 sin 2 Θ + K 2 sin 4 Θ, where K 1 and K 2 are the first and the second anisotropy constants and Θ is the angle between the c-axis and the magnetization direction, was determined using the Sucksmith-Thompson method [14].…”

“…The increase of Fe-Fe distances and the additional electrons donated from hydrogen atom into conduction band modify the electronic structure and, therefore, the exchange and anisotropic interactions in these metallic systems. This results in changes of bulk magnetic characteristics of the compounds such as the Curie temperature T C , the spontaneous magnetic moment M s and the magnetic anisotropy energy E a [1][2][3][4][5][6][7][8]. Contribution to the magnetism from the Fe sublattice is very important in R 2 Fe 14 B because it is origin of the high T C and M s values.…”

Influence of doping elements (Y, Fe, V) on magnetic properties of RM2(R = Gd, Er; M = Fe, Co, Ni) Laves phases and their hydrides

“…Basic intermetallics and alloys and their hydrides attract interest as objects for fundamental investigations and for practical application in the production of magnetic materials, hydrogen accumulators, metal hydride electrodes, etc. [1][2][3].…”

“…As it is seen from the data presented in Table 1 The magnetic properties of RMn 2 Laves phase compounds as well as their hydrides have been extensively studied in particular with respect to the interplay between the localized moments of the rare earth and the itinerant electron magnetism of the 3d sublattice leading to a wide variety of magnetic structures and associated magnetic properties [1][2][3][13][14][15]. Also rare earth and 3d metal substitutions have systematically been investigated in several pseudobinary Laves phase systems and their associated hydrides where either the isoelectronic dilution effect of the localized 4f moment by "nonmagnetic" Y, La and Lu or the effect of electronic changes of the 3d metal subsystem was of primary interest.…”

Ferromagnetism of amorphous LaCo2 hydride

“…This study indicated that the stability of the Co moment itself is critical in LaCo 2 and is easily affected by secondary interactions. Therefore hydrogenation is one of attractive options to test such variation [3], and actually magnetic properties of some RCo 2 hydrides have already been reported [4][5][6][7]. On the other hand, since most of transition-metal Lavesphase compounds have high hydrogen absorption capacity [8], hydrogenation properties of new materials are worth investigating.…”