What does the Qur'an or Hadiths say about conducting exorcisms (aza'im) to expel jinn

Exorcisms are conducted within some branches of Christianity (Roman Catholicism), and is common within Hinduism. I believe there is also the practice of ruqya which summons jinn and demons by invoking the names of God, in order to command them to abandon their mischiefs and to repair damage that may have been caused by jinn possession, witchcraft (sihr) or the evil eye. Are exorcisms permitted within Islam? If so, under whose authority are the jinns cast out?