Antiferromagnetic materials and their properties:



1. This refers to spin alignment in an antiparallel manner in neighbouring magnetic ions resulting in zero net magnetization.


2. Magnitude of susceptibility is small and positive.

3. Temperature dependence of susceptibility: when
                                         

4. The opposite alignment of adjacent magnetic moments in a solid is produced by an (unfavourable) exchange interaction.

5. Initially susceptibility increases slightly as the temperature increases and beyond Neel temperature the susceptibility decreases with the temperature.

6. Neel temperature is the temperature at which susceptibility of the material is maximum.

7. spin alignment:

 
 
 
Eg:



FeO(ferrous oxide), MnO(Manganese Oxode), Cr2O3(chromium oxide) and salts of transition elements.

No comments:

Post a Comment

Followers