Electric field triggering the spin reorientation and controlling the absorption and release of heat in the induced multiferroic compound EuTiO3

We report remarkable results due to the coupling between the magnetization and the electric field induced polarization in EuTiO3. Using a microscopic model Hamiltonian to describe the three coupled sublattices, Eu-(spin-up), Eu-(spin-down), and Ti-(moment), the spin flop and spin reorientation phase transitions were described with and without the electric-magnetic coupling interaction. The external electric field can be used to tune the temperature of the spin reorientation phase transition TSR = TSR(E). When the TSR is tuned around the EuTiO3—Neel temperature (TN = 5.5 K), an outstanding effect emerges in which EuTiO3 releases heat under magnetic field change. The electric field controlling the spin reorientation transition and the endo-exothermic processes are discussed through the microscopic interactions model parameters.