electric-field-driven magnetic entropy change*

Materials in which more than one type of caloric effects can be driven simultaneously by a single external field (magnetic, electric, or stress) have attracted much attention. An electric-field-driven magnetic entropy change termed magnetoelectrocaloric effect (MECE) is anticipated in multiferroic materials, where the magnetism and electricity are strongly correlated in a single material. Since no electric current is necessary, the energy dissipation of MECE due to Joule heating is expected to be negligibly small. We report an experimental demonstration of MECE in multiferroic GdFeO₃, which possesses the controllability of magnetism and ferroelectric polarization by an external electric field below the ferroelectric transition temperature. The temperature of the magnetic material changes when an external electric field of 25.6 kV/cm is suddenly applied or removed. Our experiments show the entropy change induced by MECE is largest just below the ordering temperature of Gd moments, suggesting that the ferroelectric transition affects MECE. The observed MECE is estimated to show an energy efficiency comparable or higher than typical magnetocaloric effects and adiabatic nuclear demagnetization. Our observation provides a proof-of-concept of MECE in multiferroics.