Laves phase compounds magnetostriction

As a property of anomalously high magnitude in cubic Laves phase compounds of rare earth metals such as Fe2(Tbo.3Dyo.7), which are the basis of magnetostrictive materials serving as magnetostrictive transducers and sensors [3.3]. 

The appearance of a perpendicular anisotropy in the mixed state of both amorphous and crystalline structure, where the magnetostriction becomes hard was reported by Miyazaki et al. (1997) for the (Tbo.3Dyo.7)o.33Feo.67 films fabricated above 673 K (400"C) (see fig. 17). Study of the thermal stability and the reproducibihty of those films was also carried out. For films prepared with substrate temperatures above 673 K (400"C), the magnetostriction changes remarkably after 3 months. This is due to aging effects, which lead to the formation of the Laves phase (Tb,Dy)Fe2 compound. 

An atomic model for the anisotropic magnetostriction based upon the structure of the cubic Laves phase C15 compounds has been proposed by Clark et al. (1976) and Cullen and Clark (1977). In this model, potentially huge values of Aim,... 

Fig. 15.4. Model of magnetostriction in Laves phase RFcj compounds (a) M (111J, (b) Af [100J Open circles, O, denote atoms above plane of figure broken circles, C, denote atoms below (taken from Clark et al., 1976).

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