AP-02 Harnessing Exchange Bias and Magnetic Proximity Effects for Superconducting Spintronics: A Novel GdN/FeMn Heterostructure
Creators: Vansh Singhal
P. Sharma
B. Dutta and A. Pal
Publisher: name: IEEE
Year: 2025

Exchange bias after being first demonstrated in 1956 by Meiklejohn and Bean (M-B) [1,2] has Garnered significant attention due to its potential application in High density information storage[3]. Currently, most studies and devices incorporating exchange bias phenomena focus on ferromagnetic metals, which can suffer from eddy current losses at high frequencies. Therefore, the need for ferromagnetic insulators in exchange bias effects and their utilization in superconducting spintronics is highly desirable.[4] In this study, we present a novel exchange bias phenomenon in a ferromagnetic insulator, GdN (T_C ~ 35 K), and an antiferromagnet, FeMn (T_N ~ 470 K). Two intriguing points are highlighted: (1) the unconventional exchange bias in the T_C << T_N system, which exhibits a interplay of Type-I and Type-II coercivity[5,6] with varying FeMn thickness, and (2) the observed reduction in the saturation magnetization of GdN with increasing FeMn thickness. Concurrently, the exchange bias field increases with increasing FeMn thickness. Which eliminates the possibility of dead layer formation in GdN with increasing the FeMn thickness.References: [1] W.H. Meiklejohn, C.P. Bean, Phys. Rev. 102 (1956) 1413. [2] W.H. Meikleiohn, C.P. Bean Phys. Rev. 105 (1957) 904. [3] H. Neal Bertram, Theory of Magnetic Recording, Cam-bridge University Press, Cambridge, 1994. [4] Appl. Phys. Lett. 115, 032403 (2019) [5] M. G. Blamire, M. Ali, C.-W. Leung, C. H. Marrows, and B. J. Hickey Phys. Rev. Lett. 98, 217202 [6] M. D. Stiles and R. D. McMichael, Phys. Rev. B 60, 12 950(1999); M. D. Stiles and R. D. McMichael, Phys. Rev. B 63, 064405 (2001).
Exchange bias after being first demonstrated in 1956 by Meiklejohn and Bean (M-B) [1,2] has Garnered significant attention due to its potential application in High density information storage[3]. Currently, most studies and devices incorporating exchange bias phenomena focus on ferromagnetic metals, which can suffer from eddy current losses at high frequencies. Therefore, the need for ferromagnetic insulators in exchange bias effects and their utilization in superconducting spintronics is highly desirable.[4] In this study, we present a novel exchange bias phenomenon in a ferromagnetic insulator, GdN (T_C ~ 35 K), and an antiferromagnet, FeMn (T_N ~ 470 K). Two intriguing points are highlighted: (1) the unconventional exchange bias in the T_C << T_N system, which exhibits a interplay of Type-I and Type-II coercivity[5,6] with varying FeMn thickness, and (2) the observed reduction in the saturation magnetization of GdN with increasing FeMn thickness. Concurrently, the exchange bias field increases with increasing FeMn thickness. Which eliminates the possibility of dead layer formation in GdN with increasing the FeMn thickness.References: [1] W.H. Meiklejohn, C.P. Bean, Phys. Rev. 102 (1956) 1413. [2] W.H. Meikleiohn, C.P. Bean Phys. Rev. 105 (1957) 904. [3] H. Neal Bertram, Theory of Magnetic Recording, Cam-bridge University Press, Cambridge, 1994. [4] Appl. Phys. Lett. 115, 032403 (2019) [5] M. G. Blamire, M. Ali, C.-W. Leung, C. H. Marrows, and B. J. Hickey Phys. Rev. Lett. 98, 217202 [6] M. D. Stiles and R. D. McMichael, Phys. Rev. B 60, 12 950(1999); M. D. Stiles and R. D. McMichael, Phys. Rev. B 63, 064405 (2001).