Neodymium magnets, especially large ones, are extremely powerful. Don’t ever let the magnets snap together, unless you absolutely need to for the experiment. The snapping force of two neodymium magnets is powerful enough to shatter a human finger and break bones. Also, some of the following experiments involve high heat. Take necessary precautions around high heat, such as safety goggles, protective clothing and gloves.
Learning the Basics of Magnetism
You probably don’t need to do an experiment to learn that two magnets can either attract or repel each other. However, you probably don’t know the exact properties of the magnets that allow them to do this. Unfortunately, you probably don’t have the equipment to measure magnetic fields or do complicated experiments to tell you exactly how magnets tick. That is what research is for. However, you can learn some basic ideas about magnetic polarity, which is the root cause of magnetic repulsion and attraction. First, make sure you have a few neodymium magnets in a bar shape. Unfortunately, you will be destroying some of these. The first experiment involves chopping a magnet in half to observe how the poles realign themselves after doing so. Allow two bar magnets to attract and come together end-to-end. Then, mark the two sides that attract with one color of marker, and the other ends with another color. Now, take them apart and snap one magnet in half with a hammer and chisel. Make sure you do this safely. Take the two snapped segments and color the ends that were just created the color that is opposite the other end. Finally, observe whether or not all three magnets behave as their colors say they should. You should record whether, on all three magnets, ends of the same color attract or repel.
Moving On to the Curie Point
This is by far the most fun experiment with magnetism. Take a small sample of neodymium magnet and remove its outer shell. This shell could be made of plastic or metal, but will need to be removed to avoid burning harmful fumes. As with burning most relatively unknown substances, it is recommended one wears some sort of mask or respirator. Once the shell is removed, test to make sure that the magnet still attracts things such as paper clips. After you know it does, take a propane torch and heat the magnet until it becomes slightly red hot. If you have a device such as a thermocouple and the proper equipment for operating it at high temperatures, you can use it to measure the temperature of the magnet. With a thermocouple, heat the magnet until it is at about 240 degrees Celsius. Taking it to red hot is a bit excessive, but it is hard to otherwise know whether you have heated it sufficiently if you can’t measure the temperature. Now, try the magnet again on the paper clips. If you heated it properly, it shouldn’t act as a magnet. This is because it has been heated past its Curie Point, or the temperature at which the magnet loses its magnetic properties. If necessary, repeat the experiment with other types of magnets to observe how they lose their magnetism due to the effects of heat.