The giant electrocaloric effect in EuTiO3 nanowires near room temperature

• The giant EC effects (15–20 K) in EuTiO3 nanowires are revealed for the first time.
• The maximum of EC effects at room temperature can be obtained by adjusting radius and external tensile stress.
• The adiabatic temperature changes can be enhanced by increasing the change of applied electric fields.
• An operating temperature range of more than 100 K has been obtained.

A phenomenological thermodynamic model is employed to investigate electrocaloric effect in EuTiO3 nanowires, in which the effects of surface tension, gradient, external stress, nanowires radius and so on are considered. We are surprised that the decrease in size and the increase in external tensile stress can significantly enhance the electrocaloric effect of EuTiO3 nanowires under the same applied electric filed. Giant adiabatic temperature changes (ΔT = 15–20 K) are achieved near room temperature by controlling the radius of EuTiO3 nanowires and applied external electric fields, which is much higher than the previous results obtained in many other isomorphic electrocaloric materials. The large electrocaloric effects suggest the potential application for micro-nanodevice in refrigeration.