Exchange Bias Between Coexisting Antiferromagnetic and Spin-Glass Orders

Published May 28, 2021

Schematic of the co-existence of antiferromagnetism and spin glass orders in FeXNbS2

A pane of window glass and a piece of quartz are both are transparent to light, but their atomic structure is very different. Quartz is crystalline at the atomic level while window glass is amorphous. This can also occur with magnetism at the atomic level in solids containing magnetic states such as antiferromagnetism (ordered) and spin-glass (disorded). This work describes the interaction (exchange bias) between ordered and disordered magnetic states and how the magnetic properties of the material are altered as a result.

What did scientists discover?

MagLab users have demonstrated the potential of combining ordered and disordered magnetic phases to greatly increase the exchange bias in materials. Additionally, the illumination of disorder's role in the physics of exchange bias in a the constraints of a single crystal is a breakthrough.

Why is this important?

Exchange bias is a critical component to a variety of devices such as spin-valves, which are used extensively in high density magnetic storage, and has potentially more exotic applications, such as voltage-mediated magnetic switching for logic devices.

Who did the research?

Eran Maniv^1,2, Ryan A. Murphy¹,Shannon C. Haley^1,2, Spencer Doyle^1,2, Caolan John^1,2, Ariel Maniv^3,4, Sanath K. Ramakrishna⁴, Yun-Long Tang^1,2, Peter Ercius², Ramamoorthy Ramesh^1,2, Arneil P. Reyes⁴, Jeffrey R. Long^1,2 and James G. Analytis^1,2

¹University of California, Berkeley, CA, USA. ²Lawrence Berkeley National Laboratory, Berkeley, CA, USA. ³Nuclear Research Center – Negev, Beer Sheva, Israel. ⁴National MagLab, Tallahassee, FL, USA.

Why did they need the MagLab?

MagLab users could only reach 7T at their home laboratory. To capture the full exchange bias response, a significant high magnetic field was needed (up to 35 Tesla), including the application of a high fixed DC magnetic fields for extended periods of time. The users stated that this capability was only available to them at the National MagLab.