as objects shrink does their magnetic field grow smaller

Discussion in 'Physics' started by Cretin, Oct 28, 2013.

  1. Cretin

    Thread Starter Member

    Dec 13, 2012
    I ask this question because I just came across an article regarding ferromagnetic materials, and F-Ram. Article said that F-Ram stores non-volatile memory through the use of a ferromagnetic layer, so memory is even stored when power is not applied to the memory chip.

    It suggested that F-RAM has a finite minimum size since the magnetic field of an object decreases as it decreases in physical size, and it would lose its ferromagnetic characteristics if constructed too small.

    Is that true across the board? Is there a proportional (linear) relationship, between an objects' size and its magnetic field strength?

    Does this also give us insight into the fact that small particles and atoms may individually act as neutral magnetic fields since they are so small, and don't exhibit any significant magnetic field strength? (although there are billions/trillions of them).
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
    Ferromagnets are ferromagnetism because the magnetic domains are aligned. As ferromagnets become smaller, each domain must become smaller. As magnets become smaller and each domain becomes smaller, the strength of the magnet decreases.

    Not all objects are ferromagnets, in fact very few are ferromagnets. Ferromagnets will attract iron and similar iron/nickel, ferrosilicon alloys and ferrites. The reference you stated is limited to ferromagnets and does not apply to all things. That being said, your question does not make sense.
  3. Danm1


    Jul 19, 2010
    The magnetic domains have some size based on the number of molecules involved so to answer your first question, yes there is a finite minimum size.

    In the relationship of field strength to size, since size is related to distance, I would say it's not linear because of the inverse square law.
    Cretin likes this.