Giant exchange bias induced by spin-glass and antiferromagnetic coupling in Fe2−xGaxTeO6 single crystals

Abstract

It is known that the utilization of exchange bias (EB) effect for data storage underscores its importance. However, achieving a giant EB effect with a small cooling field (HCF) in single-phase materials remains a challenge. This study unveils a giant EB value within a single-phase material, Fe2−xGaxTeO6 (FGTO), originating from the anchoring of spin-glass phase by antiferromagnetic order. Manipulating the relative strengths of the spin-glass and antiferromagnetic order parameters by Ga3+-substitution of Fe3+ ions in the Fe2TeO6 lattice governs the magnitude of the EB effect. It is found that FGTO single crystals synthesized via the chemical vapor transport do exhibit a remarkably large EB value as large as 1.5 T at x = 0.50 and a quite small cooling field HCF = 50 Oe. Investigations on the training effect, minor loop, and relaxation behavior unravel the intricate dynamics inherent to the spin-glass state. This study not only establishes a platform for exploring the EB effect in single-phase materials but also illuminates potential applications of FGTO in the realm of spintronics.