Vijay Kumar (28) went to the house of Mamta and took her into a room where he chopped her neck with an axe, police said.
He was admitted to a hospital for mental treatment few days back but could not take proper treatment and came home, they said, adding, after the murder, he hit his head with walls and received injuries.
Kumar has been hospitalised to the local general hospital, SHO, Tidi police station, Jitendra Singh said.