Magnetostriction compounds

M The magnetostriction of terbium alloys has already found many applications. Most recently it was discovered that its compounds can be precipitated on surfaces in highly ordered molecular arrays this promises interesting effects. 

In this handbook series, previous work on giant magnetostriction (which was mainly focused on rare-earth compounds) is excellently reviewed by Clark (1980) on Magnetostrictive Rare-Earth-Fe2 Compounds , by Morin and Schmitt (1990) on Quadrupolar... 

In these sperimagnetic structures, the subsystem magnetisations are reduced with respect to the collinear magnetic structure in the crystalline compounds. As a consequence, the saturation magnetostriction A.s is decreased. 

It should be pointed out that also in compounds based on other rare earths it was necessary to consider not only the crystal held interactions, but also the contribution of the exchange interactions, in order to understand the observed magnetostrictive effects (e.g. in the case of NdCu2 — see Rotter et al. 2002). However, in Gd compounds this exchange contribution can be studied without any ambiguity arising from the crystal held interaction, because L = 0 for Gd3+. 

The spontaneous magnetostriction has been measured by single crystal x-ray diffraction between 10 and 300 K (Kusz et al. 2000). As can be seen from figs 38 and 39, both compounds show pronounced linear as well as volume effects. Gd3Ni is characterized by a large positive spontaneous magnetostriction in a-direction (the estimated value at 0 K is (Aa/a)mag 2.9 x 10 3), whereas the effects in b- and c-direction are about two... 

Finally, we would like to point out the importance of investigations of the field-induced magnetostriction in Gd compounds. Such investigations are very important for a quantitative analysis of the spontaneous magnetostriction, which has for instance been shown by the studies on GdCu2- The lack of systematic studies of the field-induced magnetostriction in Gd compounds may be one reason why only in a few cases a quantitative description of the spontaneous magnetoelastic effects in Gd compounds has been performed. 

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