Magnetic phase transitions and giant magnetocaloric effect of EuTiO3 nanowires

• A transition mode of PM/FM skipping AFM phase is obtained.
• The giant magnetocaloric effects in EuTiO3 nanowires are revealed.
• The magnetocaloric effects can be more remarkable in nanowires with smaller radius and larger surface tension.
• The magnitude of ΔT can be enhanced obviously by increasing the change of applied electric fields.

An improved phenomenological thermodynamic theory is used to investigate the magnetic phase transitions and magnetocaloric effect of EuTiO3 nanowires by considering the radius of the nanowires and the surface tensions. We are surprised that a transition mode from paramagnetic to ferromagnetic skipping antiferromagnetic phase can appear directly in the EuTiO3 nanowires by increasing surface tension coefficients or decreasing nanowires radius. Moreover, a giant magnetocaloric effect of ΔS = 155.1 J/kgK and ΔT = 23.5 K can be obtained in this transition process for R = 0.8 nm nanowires under the applied magnetic fields change of 15 T, suggesting the potential application of EuTiO3 nanowires in low-temperature magnetic refrigeration.