Room-temperature giant magnetotranstance effect in single-phase multiferroics

摘要

Single-phase multiferroic materials are usually considered useless because of the weak magnetoelectric effects,low operating temperature,and small electric polarization induced by magnetic orders.As a result,current studies on applications of the magnetoelectric effects are mainly focusing on multiferroic heterostructures and composites.Here we report a room-temperature giant effect in response to external magnetic fields in single-phase multiferroics.A low magnetic field of 1000 Oe applied on the spin-driven multiferroic hexaferrites BaSrCo_(2) Fe_(11)AlO_(22) and Ba_(0.9)Sr_(1.1)Co_(2) Fe_(11)AlO_(22)is able to cause a huge change in the linear magnetoelectric coefficient(α_(E)=dE/dH) by several orders,leading to a giant magnetotranstance(GMT) effect at room temperature.The GMT effect is comparable to the well-known giant magnetoresistance(GMR) effect in magnetic multilayers,and thus opens up a door toward practical applications for single-phase multiferroics.