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Q & A: what can magnets be made of?

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Most recent answer: 09/18/2008
Q:
My question is, what can magnets be made of? I know of iron, but what other elements are there(if there are any)? And if there are others, can two or more elements be combined to be used in making magnets and what would they be called? My friend said something about "alnico"(aluminum and nickel combined), is this correct? Thank you!
- Jennifer Hanley (age 15)
Round Lake Bch, IL, USA
A:
Jennifer -

The most common magnetic metals are iron, nickel, and cobalt. Alloys (mixtures) that contain one or more of those elements are usually ferromagnets, meaning that the magnetic orientations of nearby atoms line up with each other on their own to make little magnetic domains. Near a permanent magnet or electromagnet, those domains tend to reorient so as to pull the magnetic material toward the other magnet, which is what you feel if you hold a permanent magnet near some iron.

Whether you can make a permanent magnet from the material depends on whether the magnetic directions of the domains tend to get stuck. If not, forces between the domains make them line up opposite to each other, and you can't make a good magnet. If they do get stuck, you can line up the domains with a big magnet, and they will stay lined up for a long time.

Alnico is an alloy made by combining aluminum, nickel, and cobalt. Thanks to the nickel and cobalt, which are both magnetic, it turns out alnico is magnetic. And the structure of alnico does allow you to make a permanent magnet out of it- the aluminum helps prevent magnetic domains from reorienting.

-Tamara (w. Mike W.)

(published on 10/22/2007)

Follow-Up #1: magnetic elements

Q:
Another magnetic element that you have forgotten is Gd. Gadolinium. I was taught in school that there are 4 magnetic elements: Ni, Fe, Co, and Gd.
- Sephiroth
Canada
A:
Gd is also magnetic.

Mikw W.

(published on 06/08/2008)

Follow-Up #2: magnetic aluminum

Q:
i saw that you can buy sheets of metal such as aluminum. can that be made magnetic and have poles? that way a real magnet could attract and repel like a normal magnet. if so, what is the easiest way possible?
- Allie Shelman (age 12)
Bonney lake WA
A:
Aluminum isn't magnetic, so that won't work. You can also buy thin sheets of steel. Some of those can be weakly magnetized by holding a strong permanent magnet near them.

Mike W.

(published on 09/18/2008)

Follow-up on this answer.