Near room-temperature intrinsic exchange bias in an Fe intercalated ZrSe2 spin glass

TL;DR

This study demonstrates that Fe intercalation in ZrSe2 creates a spin glass with strong, tunable exchange bias persisting above room temperature, offering new insights for spintronics device design.

Contribution

It reveals that magnetic disorder and frustration in Fe0.17ZrSe2 induce a robust exchange bias without long-range magnetic order, advancing understanding of magnetic frustration effects.

Findings

Exchange bias observed up to 250 K.

Magnetic frustration persists above room temperature.

Inhomogeneous environment induces exchange bias without long-range order.

Abstract

Some magnetic systems display a shift in the center of their magnetic hysteresis loop away from zero field, a phenomenon termed exchange bias. Despite the extensive use of the exchange bias effect, particularly in magnetic multilayers, for the design of spin-based memory/electronics devices, a comprehensive mechanistic understanding of this effect remains a longstanding problem. Recent work has shown that disorder-induced spin frustration might play a key role in exchange bias, suggesting new materials design approaches for spin-based electronic devices that harness this effect. Here, we design a spin glass with strong spin frustration induced by magnetic disorder by exploiting the distinctive structure of Fe intercalated ZrSe2, where Fe(II) centers are shown to occupy both octahedral and tetrahedral interstitial sites and to distribute between ZrSe2 layers without long-range structural order. Notably, we observe behavior consistent with a magnetically frustrated, and multi-degenerate ground state in these Fe0.17ZrSe2 single crystals, which persists above room temperature. Moreover, this magnetic frustration leads to a robust and tunable exchange bias up to 250 K. These results not only offer important insights into the effects of magnetic disorder and frustration in magnetic materials generally, but also highlight as design strategy the idea that a large exchange bias can arise from an inhomogeneous microscopic environment without discernible long-range magnetic order. In addition, these results show that intercalated TMDs like Fe0.17ZrSe2 hold potential for spintronics technologies that can achieve room temperature applications.