The Neodymium Magnet Origin
In ordinary life, magnets are a very common thing. And thousands of years ago, the working people in our country made the compass, one of the four great inventions, based on the characteristics of magnets. Until today, magnets are also very useful. From all kinds of special electronic equipment to the usual teaching aids and toys, magnets can often be seen. The picture below shows a horseshoe-shaped magnet. The bulk metal attracted to it is gadolinium (sound gá). This is an element that can be attracted by magnets like iron, cobalt, and nickel. It is currently widely used in the field of enhanced MRI.
We know that the main component of magnets is Fe3O4. An ordinary small magnet is made of black ferroferric oxide. However, due to the nature of Fe3O4, its attraction to iron objects will not be too strong, and its magnetism will gradually weaken over time. In this case, how can we make a magnet with stronger attraction and not suitable for decay? Under this premise, NdFeB magnets came into being.
This kind of shiny magnet with anti-corrosion treatment is NdFeB magnet, and its chemical formula is Nd2Fe14B. The most commonly used neodymium iron boron magnets are made of neodymium, iron and boron at high temperature and are the most magnetic artificial magnets so far. If iron is the core element of traditional Fe3O4, the reason why neodymium iron boron magnets have such strong magnetism is the effect of neodymium. The pieces of metal in the picture below are neodymium:
Neodymium (sound nǚ) is the fourth element of the lanthanide family of rare earth elements. Like iron, cobalt, nickel and the aforementioned gadolinium, it can also be attracted by magnets. In addition, neodymium is the more active of the lanthanide elements, so it is as easy to be oxidized as iron. This is the reason why the surface of the neodymium iron boron magnet is coated. If neodymium is used to enhance magnetism, then the role of boron should not be underestimated. This black thing is boron:
In the periodic table, boron is located to the left of carbon, so boron chemistry similar to carbon-centric organic chemistry has recently appeared. In neodymium iron boron magnets, boron is equivalent to the mediator of neodymium and iron. Boron greatly expands the maximum magnetic properties that a substance can produce while ensuring the stability of its molecular structure, making the entire magnet extremely high in magnetic performance, and even allowing it to absorb objects 640 times its own weight.