Magnetostrictive effect

Magnetorheological (MR) materials, 22 708t, 714-715, 721t Magnetostriction effect, in ferrites, 11 62-64... 

The two main types of electromechanical transducers are based on either the piezoelectric or the magnetostrictive effect. The more commonly used of which are piezoelectric transducers, generally employed to power the bath and probe type sonicator systems. Although more expensive than mechanical transducers, electromechanical transducers are by far the most versatile and widely used. 

British researcher James Joule (1818-89) discovers the magnetostrictive effect in a sample of iron that changes length in response to a magnetic field. 

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+. 

Abstract A comparison of the magnetostrictive effects in manganite and cobaltite thin... 

Because of surface contributions as well as due to interface strains, the magnetostriction of thin films is expected to be different from that observed in bulk materials. Motivated by this observation and by possible technical applications of thin films of manganites and cobaltites, we decided to present in this paper mostly results of investigations of magnetostrictive effects in thin films. It has to be mentioned that no data exist in the literature on magnetostriction of cobaltite thin films. 

The giant magnetostrictive effects observed in cobaltite films suggest that these films should be anomalously sensitive to applied strain, such as would occur if a film is grown on a poorly lattice matched substrate. It offers a possibility of tuning the properties of cobaltite films with strain [23]. 

Finally, we discuss the parastriction (or magnetostriction) effect. In an applied magnetic field the magnetoelastic coupling induces strains because of the field dependence of the quadrupolar moments of the rare-earth ions according to... 

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