I forgot the name of a theory in Magnetism

[GiacomoPaini]

Can you help me
I don't remember a theory
The name was something like
Theory ok kamp (Kemp? )
Something like this
This theory is about magnetism, more precisely about how two sources shield and influence the field)
Do you know the name thank Jacky

Thank you

 

[berkeman]

Welcome to the PF.

Maybe you are thinking of Lentz' Law? Have a look at the Wikipedia page to see if any of that information helps to jog your memory...

https://en.wikipedia.org/wiki/Magnetism

 

[SpinFlop]

Could you provide a bit more detail? What do you mean by two sources, and what generates the field? The closest match that comes to mind is the Kondo effect (starts with K) and has two 'sources' in the form of localized moments (electrons bound to specific atoms) and itinerant moments (conduction electrons moving freely through the lattice). There is a shielding process that takes place in the form of Kondo screening whereby conduction electrons cluster around a local moment in a quasi-bound state with their spins aligned opposite that of the local moment. This shielding results in a macroscopic drop in magnetization and, as a result, 'influences' the field generated by the material. Not sure if this is what you were referring to, but absent any additional information it is the best I guess I can provide.