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Magnetostriction is a property of materials that causes them to change their length along the applied magnetic field.

In the German Wikipedia an equation for the relative length change of materials is given.

$\lambda_\| = \frac{\Delta l}{l_0}$

Below this, a table shows some materials with negative and positive values for lambda. How I have to read the delta lambda? Length, before field application, minus length after? Or in reverse order?

A note. Perhaps someone remembers such experiments. For the diamagnetic materials Fe, Co and Ni the value is negative.

HolgerFiedler
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1 Answers1

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Negative means shorter. For anisotropic materials (e.g. single crystals), $\lambda$ may be a tensor. This means the changes in size do not necessarily occur solely along the direction of the field (i.e. the shape may change).

Roger Wood
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