Before exploring the applications of rare earth and neodymium magnets, it’s time to know what exactly these magnets are. First of all, neodymium magnets are a type of rare earth magnets. They are called rare earth because they are made up of the lanthanide. These are the strongest and permanent magnets which are commercially available in the world. Their features include:
- Unparalleled levels if magnetism
- Resistance to demagnetization (when compared to other magnets like alnico, ferrite and even samarium cobalt ones)
These magnets are so strong that even tiny ones are effective so much so that a magnet just 5mm long and 8mm in diameter can generate a force of above 1,700 grams in spite of weighing only 2 grams. So with these properties, all available in pocket sizes, there are bound to be major users of this substance, like:
- Hard disk drives: Hard disk drives record data by constantly magnetizing and demagnetizing a thin film of ferromagnetic material present on the disk. Apart from this, each disk is also divided into sectors and each sector contains numerous individual magnetic disks which are magnetized when the read or write head of the drive is written to the drive.
- Audio Equipment: In speakers, these permanent magnets are used right alongside a current carrying coil which assists in changing electricity into mechanical energy. For microphones, the reverse is applicable- the permanent magnet creates a magnetic field, which allows the coil to move through it, thus producing an electrical signal which is similar to the original sound made.
- Dentures: This might come as a surprise but neodymium magnets are useful in holding together replacement dentures in case of several missing teeth.
- Door catches: Neodymium magnets are pretty widely used in various residential, commercial and public building to make magnetic door catches. These magnets hold the weight of the door quite easily and with the help of the leverage provided by the door, it results in the magnets being easily separated.
- Generators and motors: These two work in reverse, as in electric motors are dependent upon a combination of an electromagnet and a neodymium magnet to convert the electric energy into a mechanical one. As said above, the opposite is true for the generator.
- MRI scanners: This is pretty obvious as MRI scanners generate a huge magnetic field which aligns the protons present in the human body in the direction if the magnetic field.
- ABS system sensors: ABS or anti-lock braking sensors uses rare earth magnets but wrapped up inside copper coils. A sensor is positioned close to the ABS reluctor ring and as the ring revolves, a voltage is introduced in the copper wire. This signal is then monitored by the computer system of the vehicle and thus used to define wheel speed.
Apart from this, they are used in lifting machinery, jewelry, bearings, levitation machines and more. In fact, these are so widely used that it is commonly regarded that without this magnet; our world would be two or three decades behind on technological advancement.