Magnetic-field-induced polarization and magnetocapacitance in quantum paraelectric EuTiO3

EuTiO3 is a quantum paraelectric as well as an antiferromagnet. The most attractive property for EuTiO3 is the magnetoelectric coupling effect. In the present work, we investigate the influence of the external fields on EuTiO3, including the electric field E and magnetic field h. The application of the electric field counteracts the quantum fluctuation and forces the system into an electrically ordered state. The applied magnetic field directly induces the fluctuation of the spin-pair correlation and indirectly influences the dielectric behaviors through the magnetoelectric coupling. In addition, we notice that the contribution of the magnetic field depends closely on the temperature condition and the electric field background. The (p, h, E, T) and (ε, h, T) diagrams are presented showing the temperature, magnetic and electric field dependence of the polarization and the dielectric capacitance. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)