I am afraid there is no general result (as far as I know) to say like that. It directly depends on the material.

I think in the single crystals with high purity.

Dear Bagher Aslibeiki ,

First of all there are many types of magnetic anisotropy ( like Magnetocrystalline  , Magnetoelastic , Shape and surface anisotropy etc. ) which anisotropy are you interested in ??

All these Anisotropies are additive in nature (with positive or negative sign) , so they may affect the resultant value of magnetic anisotropy.

There is no General result , as anisotropy depends upon shape as well as stress and other factors too But for specific conditions you can ask such question.

Dear Sandeep

Thanks

Magnetocrystalline anisotropy of Bulk materials differs from corresponding nanoparticles and films. I need to know which one has the maximum value?

That one which will have the strongest/weakest magnetic field on the chosen particular direction (since the difference in strongest/weakest will give you the maximum values). In any way it is an ensemble average and the strength is adding up. You can talk about the magnetic properties taking only one atom and its surroundings too.

For a given composition only the  single crystal will exhibit the max anisotropy at a given temperature.