Enhanced magneto-electric effect in manganite tricolor superlattice with artificially broken symmetry

【摘要】 The magneto-electric effect in magnetic materials has been widely investigated, but obtaining an enhanced magnetoelectric effect is challenging. In this study, tricolor superlattices composed of manganese oxides—Pr_0.9Ca_0.1MnO₃,La_0.9Sr_0.1MnO₃, and La_0.9Sb_0.1MnO₃—on（001）-oriented Nb:SrTiO₃ substrates with broken space-inversion and timereversal symmetries are designed. Regarding the electric polarization in the hysteresis loops of the superlattices at different external magnetic fields, both coercive electric field E_c and remnant polarization intensity P_r clearly show strong magneticfield dependences. At low temperatures（< 120 K）, a considerable magneto-electric effect in the well-defined tricolor superlattice is observed that is absent in the single compounds. Both maxima of the magneto-electric coupling coefficients ?E_c and ?P_r appear at 30 K. The magnetic dependence of the dielectric constant further supports the magneto-electric effect. Moreover, a dependence of the magneto-electric effect on the periodicity of the superlattices with various structures is observed, which indicates the importance of interfaces. Our experimental results verify previous theoretical results regarding magneto-electric interactions, thereby paving the way for the design and development of novel magneto-electric devices based on manganite ferromagnets.更多还原

【Abstract】 The magneto-electric effect in magnetic materials has been widely investigated, but obtaining an enhanced magnetoelectric effect is challenging. In this study, tricolor superlattices composed of manganese oxides—Pr_0.9Ca_0.1MnO₃,La_0.9Sr_0.1MnO₃, and La_0.9Sb_0.1MnO₃—on（001）-oriented Nb:SrTiO₃ substrates with broken space-inversion and timereversal symmetries are designed. Regarding the electric polarization in the hysteresis loops of the superlattices at different external magnetic fields, both coercive electric field E_c and remnant polarization intensity P_r clearly show strong magneticfield dependences. At low temperatures（< 120 K）, a considerable magneto-electric effect in the well-defined tricolor superlattice is observed that is absent in the single compounds. Both maxima of the magneto-electric coupling coefficients ?E_c and ?P_r appear at 30 K. The magnetic dependence of the dielectric constant further supports the magneto-electric effect. Moreover, a dependence of the magneto-electric effect on the periodicity of the superlattices with various structures is observed, which indicates the importance of interfaces. Our experimental results verify previous theoretical results regarding magneto-electric interactions, thereby paving the way for the design and development of novel magneto-electric devices based on manganite ferromagnets.更多还原