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Oxide interfaces are attracting a lot of interests not only for their crucial importance in technological applications of all-oxide devices,but also for their offering possible approaches to new,unexpected material properties and physics [1].The typical LaAlO3/SrTiO3 interface exhibits quasi-two-dimension electron gas(2DEG)properties and magnetic behaviors [2-3].The observations of magnetism at LaAlO3/SrTiO3 interface stimulate interests in finding similar oxide interfaces,which may exhibit ferromagnetism and conductivity.We investigate the electronic,ferroelectric and magnetic properties of ideal defect-free KTaO3/PbTiO3 interfaces by using density functional theory methods(including advanced techniques such as hybrid functional HSE06).Base on spin-polarize calculations,we find that both doped holes and electrons are prone to spin-polarize and thus result in local magnetic moments on atoms near the interfaces.Further research for possible magnetic ground states shows that the interface ferromagnetic states are ground states for both n-type and p-type interfaces by comparison with nonmagnetic and antiferromagnetic states.Carriers(electrons or holes)concentrate at interfaces to screen the polarization charge and thus concentration of carriers can be regulated by ferroelectric polarization.Furthermore,the interface magnetization,which closely related to carrier density,can also be tuned by ferroelectric polarization,leading to strong magnetoelectric effects at originally nonmagnetic interface of KTaO3 and PbTiO3.This suggests an illuminating approach to multiferroic materials beyond conventional single-phase multiferroics and multi-phase multiferroics such as ferroelectric/ferromagnet heterostructures.