Brady

=Title=

Temperature and Magnet Strength
= = =Introduction= I want to test if batteries are weaker or stronger in varying temperatures. I also want to see if things could be planned better if they knew what environment or condition magnets work best in. = = =Background Research=

=
I found that magnets have been known to work better in the cold. I also found a source saying that at colder temperatures the particles in the magnet line up to cause a more concentrated field. Another source said that if a magnet is heated to its Curie Point it can actually lose its magnetism. The curie point for most ceramic magnets is around 480 degrees Celsius or 900 degrees Fahrenheit.===== = = =Hypothesis= After doing some background research I made the hypothesis that the magnets would work better in colder temperatures because the particles in the magnet will move slower causing them to line up more often, which will concentrate the magnetic field. = = =Materials= 2 ceramic magnets, dry ice, metal bar, 60 paper clips, gloves, bowl, ruler = = =Methods= First, I gathered my supplies and put on my gloves. Next, I broke up the dry ice and put it in a bowl. Then, I put one of the magnets on a piece of dry ice and surrounded it with other pieces of dry ice. While I waited for the first magnet to cool I tested the other magnet at room temperature by lowering it over paperclips to see how many it picked up. I also lowered a metal bar over the magnet until it picked the magnet up and measured how high the bar was. After one hour I took the first magnet out of the ice and ran the same tests. = = =Results= The normal magnet picked up 24 out of sixty paperclips and clung to the bar about two centimeters away. The magnet in the dry ice picked up 25 out of 60 paper clips and clung to the metal bar only millimeters higher than the regular magnet.

=Conclusion= The cold magnet was only slightly stronger than the magnet at room temperature, but if I had used liquid nitrogen or something colder than dry ice it probably would have worked better. = = =References=

"The Journal of Magnetism and Magnetic Materials"

"Magnetic Magic"

http://www.coolmagnetman.com/magtypes.htm

http://www.newton.dep.anl.gov/askasci/phy00/phy00146.htm

http://www.x-magnet.net/faq.html

=Questions for Further Study=

If I use liquid nitrogen instead of dry ice will it have a better effect on the magnet?

What is the temperature of the magnet?

Can I demagnetize a magnet?