Design of anti-site disorder for tunable spontaneous exchange bias: Mn-Ni-Al alloys as a case

A reasonable design not only accelerates the discovery of materials but also optimizes the performance of existing materials. Here, we report that microscopically the active design of the degree of anti-site disorder from 20% to 27% can be realized by tuning the Al content in Mn50Ni50-xAlx. Mesoscopically, the control of the pinning interface and the magnetic cluster size of the spin glass required for spontaneous exchange bias (SEB) are achieved. The P value reflecting the magnetic cluster size can be changed from 0.0067 to 0.0437. Finally, macroscopically, SEB in Mn50Ni50-xAlx (x = 10–15) is achieved, and the largest SEB field (1370 Oe) is obtained in Mn50Ni37Al13 with the largest degree of anti-site disorder and the smallest magnetic cluster size. Our results demonstrate that anti-site disorder can be not only an effective method for obtaining SEB but also a tool for stabilizing SEB in a wide elemental content window.