Talk:Electrostriction

quote:

"When an electric field is applied to the dielectric, the opposite sides of the domains become differently charged and attract each other, reducing material thickness in the direction of the applied field (...)"

Now have a look at this picture

  -------E---------------------------->
  -------E---------_____________------>
  -------E---------|-(-)---(+)-|------>
  -------E---------|-(-)---(+)-|------>
  -------E---------|-(-)---(+)-|------>
  -------E---------|-(-)---(+)-|------>
  -------E---------|-(-)---(+)-|------>
  -------E---------|-(-)---(+)-|------>
  -------E---------_____________------>
  -------E---------------------------->

Effect 1: I see that the left side of the body feel a force to the left because the electrons are inside the outside electric field. The right side will be pushed to the right by the electric field because of the positive charge.

Effect 2: Yes, the material will create a field that lets the charges attract each other and make the material slim and high.

But if you think about it you will find out that effect 2 must be smaller than effect 1 because the electric field created by the charge on one side of the body cannot create an electric field that is greater than the outside field E

The current version of the article neglects the imho greater effect 1 and presents only effect 2

Reply from material scientist: You are completely correct. The article was directly wrong, and I have edited it. The fact that electrostriction always cause strain (elongation) along the electric field is well known throughout the literature. See for example: Juergen Roedel, Wook Jo, Klaus T. P. Seifert, Eva-Maria Anton, Torsten Granzow, and Dragan Damjanovic. "Perspective on the development of lead-free piezoceramics". In: J. Am. Ceram. Soc. 92.6 (2009), pp. 1153?1177. doi: 10.1111/j.1551-2916.2009.03061.x. 129.241.82.145 (talk) 08:37, 26 August 2014 (UTC)[reply]

Thanks for pointing this out. The french version of this page fr:électrostriction still has the other narrative in it (contraction along the electric field), and I was stumbling over the blatant contradiction. DieHenkels (talk) 15:05, 8 December 2023 (UTC)[reply]

electrostriction in metals[edit]

from the article I interpret this as a phenomenon pertaining to dielectrics only, but when googling "electrostriction metals" the top hit is a journal article that measures this effect also for metals. I do not have access, but the abstract is the following:

"We examine electrostriction in ellipsoidal samples of dielectrics and metals. We show that electrostriction in metals is independent of the external shape of the sample, whereas in dielectrics electrostriction is a quadratic function of the shape parameter." 2A01:799:952:4500:25C2:E459:88F:5C64 (talk) 12:11, 25 January 2024 (UTC)[reply]