Spontaneous magnetostriction

Various experimental methods have been developed for investigating the magnetoelastic properties of thin films and nanoscale magnetic systems. In the following subsections, we discuss the most important ones (i) the magnetoelastic cantilever, (ii) strain induced anisotropy, (iii) magnetostriction in spin valves, (iv) strain modulated ferromagnetic resonance, (v) secondary-electron spin-polarisation, and (vi) strain-induced anisotropy due to the spontaneous strains. 

Among the presented systems in this chapter, GdCu2 is one for which a variety of studies dealing with the magnetic properties and spontaneous as well as field-induced magnetostriction have been done in the past and also more recently (Rotter et al. 2001a). 

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... 

Summary of the spontaneous magnetostriction in non-cubic systems showing pronounced anisotropic effects, ordered with respect to the size of the effects. The presented... 

Summary of the spontaneous magnetostriction (estimated values at 0 K) of the systems with very small or not determined (n.d.) anisotropic effects. The table is ordered... 

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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