title: Antiferromagnetic proximity effect in epitaxial CoO/NiO/MgO(001) systems.
abstract: Magnetic proximity effect between two magnetic layers is an important focus of research for discovering new physical properties of magnetic systems. Antiferromagnets (AFMs) are fundamental systems with magnetic ordering and promising candidate materials in the emerging field of antiferromagnetic spintronics. However, the magnetic proximity effect between antiferromagnetic bilayers is rarely studied because detecting the spin orientation of AFMs is challenging. Using X-ray linear dichroism and magneto-optical Kerr effect measurements, we investigated antiferromagnetic proximity effects in epitaxial CoO/NiO/MgO(001) systems. We found the antiferromagnetic spin of the NiO underwent a spin reorientation transition from in-plane to out-of-plane with increasing NiO thickness, with the existence of vertical exchange spring spin alignment in thick NiO. More interestingly, the Néel temperature of the CoO layer was greatly enhanced by the adjacent NiO layer, with the extent of the enhancement closely dependent on the spin orientation of NiO layer. This phenomenon was attributed to different exchange coupling strengths at the AFM/AFM interface depending on the relative spin directions. Our results indicate a new route for modifying the spin configuration and ordering temperature of AFMs through the magnetic proximity effect near room temperature, which should further benefit the design of AFM spintronic devices.
authors.affiliation: Department of Physics, State Key Laboratory of Surface Physics and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, People's Republic of China.
authors.forename: Q
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Physics, State Key Laboratory of Surface Physics and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, People's Republic of China.
authors.forename: J H
authors.initials: JH
authors.lastname: Liang
authors.affiliation: Department of Physics, State Key Laboratory of Surface Physics and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, People's Republic of China.
authors.forename: Y M
authors.initials: YM
authors.lastname: Luo
authors.affiliation: Department of Physics, State Key Laboratory of Surface Physics and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, People's Republic of China.
authors.forename: Z
authors.initials: Z
authors.lastname: Ding
authors.affiliation: Department of Physics, State Key Laboratory of Surface Physics and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, People's Republic of China.
authors.forename: T
authors.initials: T
authors.lastname: Gu
authors.affiliation: Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, Dresden 01187, Germany.
authors.forename: Z
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, Dresden 01187, Germany.|National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan, Republic of China.
authors.forename: C Y
authors.initials: CY
authors.lastname: Hua
authors.affiliation: National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan, Republic of China.
authors.forename: H-J
authors.initials: HJ
authors.lastname: Lin
authors.affiliation: National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan, Republic of China.
authors.forename: T W
authors.initials: TW
authors.lastname: Pi
authors.affiliation: Department of Physics, Kyung Hee University, Seoul 130-701, Republic of Korea.
authors.forename: S P
authors.initials: SP
authors.lastname: Kang
authors.affiliation: Department of Physics, Kyung Hee University, Seoul 130-701, Republic of Korea.
authors.forename: C
authors.initials: C
authors.lastname: Won
authors.affiliation: Department of Physics, State Key Laboratory of Surface Physics and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, People's Republic of China.
authors.forename: Y Z
authors.initials: YZ
authors.lastname: Wu