Long term magnetic repulsion with permenant magnets?

[carmatic]

i have a set of neodynium magnets which i am using for a magnetic levitation project... will the constant exposure to an opposing magnetic field weaken the magnets over time? are 'permenant' magnets really permenant?

 

[Meir Achuz]

The reverse magnetic field can tend to demagnetize. The extent depends on the material of the magnet and temperature.

 

[carmatic]

the coercivity of neodymium is 1.2 , which is supposed to be greater than most materials... this means that , in the same conditions, neodymium would keep its magnetic strength for longer than most materials, but not indefinitely?