Copper can be magnetic This depends on what you mean by "magnetic." Magnets are materials whose crystal structures have been aligned so as to generate magnetic fields; most metals, however, do not create magnetic fields because their atoms do not line up into an alignment which creates such fields.
Electromagnetism is one of the easiest and most straightforward ways to turn non-magnetic metals magnetic, involving encasing copper with another conductive material like iron and running an electric current through it, creating an intense electromagnetic field around it that remains when power is removed, returning it back to being non-magnetic once current stops flowing through.
Other methods involve subjecting copper wire or other forms of metal to an external magnetic field and temporarily magnetizing it - another popular approach used often with copper.
Other methods for magnetizing copper include exposing it to an external magnetic field:
Create an Electrical Eddy Current
Electrical eddy currents are similar to magnetic fields created by an electric current; when a magnet moves near copper or other metals, it causes these electrical eddy currents to form near them, which then interact with its magnetic field either to attract or repel metal objects.
Scientists have used soccer-ball-shaped molecules made up of carbon atoms known as "buckyballs" to induce magnetism in copper and manganese. Because buckyballs tend to strip electrons out of other materials, they are especially adept at encouraging magnetic properties from non-magnetic elements.
By layering copper and manganese films over layers of these buckyballs, they were able to induce partial magnetism both within the metals themselves as well as their surrounding buckyballs. After applying an external magnetic field and then withdrawing it, an inducible magnetism still persisted - although only about 10% as intensely.
These results, published in Nature Nanotechnology, indicate that buckyballs could be used to magnetize other non-magnetic metals besides iron. This represents a breakthrough, as it proves that internal electronic structures of certain non-magnetic materials may provide sufficient energy benefits to align electrons and create magnetism.
Increased U to an Outrageous Level
One factor that determines whether an element can become magnetic is its U value - defined as the number of unpaired electrons. When measuring U for their copper samples, researchers discovered it to be far less than expected according to Stoner's criteria, suggesting they should have been non-magnetic instead of being magnetic.
Utilizing Electromagnetism to Convert Copper into Magnets
Electromagnetism is an efficient way to transform copper into magnets, but requires significant energy consumption. Producing electrical eddy current takes some time and can be costly. Furthermore, electromagnets may only produce limited voltage or current levels.