Answer
It is impossible to have a magnetic wave without any electric component.
Work Step by Step
Faraday's law states that a changing magnetic field produces an electric field. If there is a magnetic wave, then the magnitude of the field would be changing continuously as the wave propagates. By Faraday's law, this changing magnetic field would produce an electric field perpendicular to the magnetic field. Therefore, it is impossible to have a magnetic wave without any electric component.
