Tuning magnetic spirals beyond room temperature with chemical disorder

Frustrated magnets with spiral magnetic orders are of high current interest due to their potential for spintronics and low-power magnetoelectric devices. However, their low magnetic order temperatures (typically <100K) greatly restrict their fields of application. Researchers of PSI have demonstrated that the stability domain of the spiral phase in the perovskite YBaCuFeO₅ can be enlarged by more than 150K through a controlled manipulation of the Fe/Cu chemical disorder. Moreover, they showed that this novel mechanism can stabilize the magnetic spiral state of YBaCuFeO₅ above the symbolic value of 25C. These findings demonstrate that the properties of a magnetic spiral, including its wavelength and stability range, can be engineered through the control of chemical disorder, offering a great potential for the design of materials with magnetoelectric properties beyond room temperature. This study, fully conducted at the PSI, was an output of the project 'Magnetoelectric coupling at RT: investigating novel routes' funded by the Swiss National Science Foundation.