TY - JOUR
KW - Thin films
KW - Substrates
KW - Hysteresis
KW - Electric fields
KW - Multiferroics
KW - Ferroelectric materials
KW - Magnetism
KW - Exchange coupling
KW - Ferroelectricity
KW - Ferroelectric domains
KW - Strontium titanates
KW - Multiferroic materials
KW - Strontium alloys
KW - Ferroelectric films
KW - Coercive force
KW - Energy dissipation
KW - Magnetoelectronics
KW - Neutron diffraction
KW - Silicon wafers
KW - Crystallographic directions
KW - Electric-field-induced switching
KW - Intrinsic Magnetoelectric couplings
KW - Magnetoelectronic devices
KW - Remanent magnetization
KW - Cobalt
AU - T Gao
AU - X Zhang
AU - W Ratcliff II
AU - S Maruyama
AU - M Murakami
AU - A Varatharajan
AU - Z Yamani
AU - P Chen
AU - K Wang
AU - H Zhang
AU - R Shull
AU - L.A Bendersky
AU - J Unguris
AU - Ramamoorthy Ramesh
AU - I Takeuchi
AB - Electric-field (E-field) control of magnetism enabled by multiferroic materials has the potential to revolutionize the landscape of present memory devices plagued with high energy dissipation. To date, this E-field controlled multiferroic scheme has only been demonstrated at room temperature using BiFeO3 films grown on DyScO3, a unique and expensive substrate, which gives rise to a particular ferroelectric domain pattern in BiFeO3. Here, we demonstrate reversible electric-field-induced switching of the magnetic state of the Co layer in Co/BiFeO3 (BFO) (001) thin film heterostructures fabricated on (001) SrTiO3 (STO) substrates. The angular dependence of the coercivity and the remanent magnetization of the Co layer indicates that its easy axis reversibly switches back and forth 45° between the (100) and the (110) crystallographic directions of STO as a result of alternating application of positive and negative voltage pulses between the patterned top Co electrode layer and the (001) SrRuO3 (SRO) layer on which the ferroelectric BFO is epitaxially grown. The coercivity (HC) of the Co layer exhibits a hysteretic behavior between two states as a function of voltage. A mechanism based on the intrinsic magnetoelectric coupling in multiferroic BFO involving projection of antiferromagnetic G-type domains is used to explain the observation. We have also measured the exact canting angle of the G-type domain in strained BFO films for the first time using neutron diffraction. These results suggest a pathway to integrating BFO-based devices on Si wafers for implementing low power consumption and nonvolatile magnetoelectronic devices. © 2017 American Chemical Society.
BT - Nano Letters
DO - 10.1021/acs.nanolett.6b05152
LA - eng
M1 - 5
N1 - cited By 20
N2 - Electric-field (E-field) control of magnetism enabled by multiferroic materials has the potential to revolutionize the landscape of present memory devices plagued with high energy dissipation. To date, this E-field controlled multiferroic scheme has only been demonstrated at room temperature using BiFeO3 films grown on DyScO3, a unique and expensive substrate, which gives rise to a particular ferroelectric domain pattern in BiFeO3. Here, we demonstrate reversible electric-field-induced switching of the magnetic state of the Co layer in Co/BiFeO3 (BFO) (001) thin film heterostructures fabricated on (001) SrTiO3 (STO) substrates. The angular dependence of the coercivity and the remanent magnetization of the Co layer indicates that its easy axis reversibly switches back and forth 45° between the (100) and the (110) crystallographic directions of STO as a result of alternating application of positive and negative voltage pulses between the patterned top Co electrode layer and the (001) SrRuO3 (SRO) layer on which the ferroelectric BFO is epitaxially grown. The coercivity (HC) of the Co layer exhibits a hysteretic behavior between two states as a function of voltage. A mechanism based on the intrinsic magnetoelectric coupling in multiferroic BFO involving projection of antiferromagnetic G-type domains is used to explain the observation. We have also measured the exact canting angle of the G-type domain in strained BFO films for the first time using neutron diffraction. These results suggest a pathway to integrating BFO-based devices on Si wafers for implementing low power consumption and nonvolatile magnetoelectronic devices. © 2017 American Chemical Society.
PB - American Chemical Society
PY - 2017
SP - 2825
EP - 2832
T2 - Nano Letters
TI - Electric-Field Induced Reversible Switching of the Magnetic Easy Axis in Co/BiFeO3 on SrTiO3
VL - 17
SN - 15306984
ER -