What is magnetic moment?

02.05.2021|Dariusz Ostrowski

If someone wants to, they can easily find a series of formulas describing magnetic moment. However, mathematical calculations are usually not necessary for anyone; what matters more is understanding the phenomenon itself. To define magnetic moment, we should start by acknowledging that numerous objects in our world are magnets. Starting from the smallest, invisible to the naked eye, electrons and atoms, through chunks of magnetite, and man-made magnets, all the way to our entire planet. Which, as it turns out, is a massive, powerful magnet from which we and plants and animals benefit. Each of these objects possesses a magnetic field that spreads between its poles in the form of lines. If some physical object is placed in such a field and begins to rotate under the influence of forces acting on it, we then say it has a magnetic moment. In practice, this moment depends on the force acting on the dipole, or rather, the torque. If the lines of the object align with the lines of the field in which the object was placed, it will remain motionless. This can be best illustrated by a simple compass needle. Because it is magnetized, it aligns itself along the Earth's magnetic lines; if deflected, it will move until it achieves stability.

Magnetic Moment in Practice

Although few people think about magnetic moments in their daily lives, this phenomenon has significant practical importance. This is because magnets themselves are widely used in both everyday life and industry, and many of these applications involve motion. Just like the previously mentioned magnetic needle, various motors and other devices containing magnets are examples. The stronger the magnet, the greater its magnetic moment, and designers of devices often take advantage of this relationship. Strong magnets allow achieving the required parameters with much less material. This translates to the size and performance of the device, and ultimately, its costs. Neodymium magnets are known for having particularly large magnetic moments. One of the most common uses of magnets is in motors. In motors, electrical energy flowing through the device is converted into mechanical energy. There are many types of motors, differing in their power source, application, and size, but their common feature is the utilization of the magnetic moment phenomenon. One of the motor components is a permanent magnet, while the other carries an electric current, generating an electromagnetic field. The interaction of these elements results in rotational motion.

Heat-resistant magnets

Standard magnets lose power in heat. If your project requires operation at high temperatures, ask us about the high-temperature series (H, SH, UH).