Field-induced magnetostriction

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). 

Figure 35 shows the field induced magnetostriction for external fields along the a-, b- and c-axis (Rotter et al. 2001a). All measurements were done with increasing... 

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. 

Kadomtseva et al. (2000) measured thermal expansion and longitudinal and transverse magnetostriction in pulsed magnetic fields up to 25 T in Lai - Sr MnOj single crystals (x = 0.1,0.125 and 0.15). The results were ascribed to a suppression of the O phase and field-induced transitions to a new orbital-ordered ferromagnetic state. 

Perturbation theory is no longer applicable when the field-induced deformations reach giant values 10 (see fig. 10). In strong fields Ho > 15 kOe) one must take into account the effect of deformation in the energy spectrum of Tm + ions, i.e., one should use solutions of self-consistent field equations for the electronic order parameters Op) in this case the dependence of magnetostriction on H becomes nonlinear, which was observed experimentally by Al tshuler et al. (1980) and Bondar et al. (1988). 

The anisotropy (as well as temperature and magnetic field dependences) of the induced magnetostriction in LiHoF4 and Tb2Ti207 crystals, measured by Al tshuler et al. (1984)... 

The longitudinal induced magnetostriction can be written as a function of temperature and external magnetic field in accordance with eqs. (233) and (241) ... 

Fig. 28. Temperature dependence of the induced magnetostriction in LiTbp4 along the 20kOe field L [001]. The dashed curve represents the calculated values of magnetostriction obtained with eq. (253).

Depending on their base metal they exhibit characteristic differences of technical significance. Accordingly they are classified into three groups Fe-based alloys, Co-based alloys, and Ni-based alloys. The characteristic variation of their intrinsic magnetic properties saturation polarization Is, saturation magnetostriction A.S, and the maximum field induced magnetic... 

Due to their high piezoelectric response, electrostriction in ferroelectrics, induced by an applied electric field, can be used as strain-inducing components (just as ferromagnetic materials can be exploited for their magnetostriction). Thus barium... 

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