Hi everyone, Is there a material which, inside a solenoid, immediately or in a very short period of time gets magnetized as current is switched on and then stays magnetized for a while if the current is switched off? For if this were true then this would mean we could derive more energy out of the system as we put in. We magnetize the material, switch off the current then use that magnet to attract magntic material to it and derive energy from it. Then as the material is demagnetized after some time we can with much less energy remove the materials which were initally attracted to the temporary magnet. Then repeat the process. Wherein lies the problem?