Strongly enhanced antiferromagnetism and giant spontaneous exchange bias in Ni₅₀Mn₃₆Co₄Sn₁₀ Heusler alloy

Abstract

An enormous spontaneous exchange bias (EB) was obtained after zero-field cooling in Ni50Mn36Co4Sn10 Heusler alloy. It can be attributed to the enhancement of antiferromagnetism, which induces a strong interaction with superferromagnetism, superspin glass, and superparamagnetism. In addition, the EB with an abrupt drop below the lower temperature of 5 K was observed, which can be interpreted as the fact that the rotation of the antiferromagnetic spins from a disordered state to a more ordered state is hindered by domain wall pinning.