adiabatic  demagnetization    This  is a technique by which temperature  of  paramagnetic substances  can  be  reduced to a temperature   near   absolute  zero.  The  system is completely insulated.  The  atomic  dipoles  are  aligned using an external magnetic  field. Then the field is switched off. The system goes to unmagnetized state on its own. When this occurs it derives the energy  required for the process from the internal energy. This causes the temperature to fall.