Question

What happens to ferromagnetic substances heated above Curie temperature?

Answer 1

Hint: We will use definitions and concepts related to ferromagnetic substance and Curie temperature to find the answer. Once we know what happens to ferromagnetic substances if it is heated above its Curie temperature then we will answer the question.

Complete answer:
Curie temperature: It is known temperature of any material above which the materials become permanently magnetized.

Ferromagnetism: It is actually a magnetic strength of an iron, cobalt, nickel and so many which are being oxidized into oxides. This strength does not depend on any other magnetic field intensity at all. Their magnetism is permanent. If we say ferromagnetism process then this means that we are talking about a process in which we found strong attraction of uncharged particles.

There are actually two types of ferromagnetism namely, magnetized and unmagnified. The unmagnified have different domains as can see in figure above with different magnetic directions. Once these are externally magnetized by external field application to ferromagnetism then they become permanent magnets.

Properties, Advantages and disadvantages, uses: After magnetized externally they become permanent. All domains are in the same direction after the magnetization process. Their curie temperature is different according to element selection. If heated greater than that then they become permanent. They have high resistibility and are cheap. Their coercivity is low and remains stable for much longer. But they are weak in terms of their magnetic fields also. They are found in making electromagnets, hard devices which we also have in our homes. Also, they are used in generators, telephones and our electric motors.
Hence, if a ferromagnetic element is heated above its Curie temperature then they become Para-magnetic magnets.

Note:
To answer this question one should know the following points thoroughly.
(1) Definition of Curie temperature.
(2) Concept of ferromagnetic materials along with their properties, advantages and disadvantages.
(3) If we see all around us then we will find any material which is used in our daily life. Most of us are familiar with telephones in which these are used.
(4) Once cobalt, nickel or iron is heated above their Curie temperature then, they will also become permanent in terms of magnetic properties.