Effect of thermal cycle on the interfacial antiferromagnetic spin configuration and exchange bias in Ni-Mn-Sb alloy

Abstract

Effect of thermal cycle on the interfacial antiferromagnetic (AFM) spin configuration and exchange bias in Ni50Mn36Sb14 alloy has been investigated. The results indicate thermal cycle can induce further martensitic transition from part of arrested FM phase to AFM phase, leading to the reconstruction of interfacial antiferromagnetic spin configuration. The shape of hysteresis loops at 5 K after cooling back can be tuned from a single-shifted loop to a nearly symmetric double-shifted loop gradually accompanied with exchange bias field increasing to peak value and then decreasing. The evolutions can be illustrated intuitively by a simple AFM bidomain model

Tuning exchange bias through zero field cooling from different remanent states above blocking temperature in Ni50Mn36Sb14 alloy

“…As reported before 7, 10, 15, 20, 21, the occurrences of double shifted hysteresis loops can be attributed to the coexistence of two types of AFM domains showing opposite EB signs at the FM/AFM interface. Hence, the above experimental results can be explained by the variation of interfacial spin configuration.…”

“…The FM spin configuration can be simplified as two FM domains with opposite directions parallel to the direction of magnetic field and the relative size depends on M R 19. Due to the FM–AFM exchange interaction, AFM spins tend to align parallel to FM spins after cooling back 7, 19, 21, resulting in an imprint of the domain pattern of FM regions into AFM regions during ZFC through T B . When a hysteresis loop is carried out below T B , a single domain structure of FM spins appears as applying a positive field while the AFM spins remain unchanged due to their large anisotropy.…”

Exchange Bias Effect in NiMnSbB Ferromagnetic Shape Memory Alloys Depending on Mn Content

“…The HEB is defined as HEB=−(H1+H2)/2. Here, H1 and H2 are the left and right coercive fields, respectively [20][21][22][23]. HEB values of Sb-13.5, Sb-13.3 and Sb-13.1 samples were calculated as 340 Oe, 600 Oe and 820 Oe, respectively.…”

Large exchange bias in magnetic shape memory alloys by tuning magnetic ground state and magnetic-field history

“…The EB behaviours of these MSMAs vary greatly by changing compositions, because the FM and AFM interactions change considerably with the variation of compositions. As a consequence, different magnetic ground states, such as FM/ AFM [12], ferrimagnetic/AFM [13], and spin glass (SG)/ AFM states [14][15][16], may form, and the unidirectional magnetic anisotropy at the interfaces between the FM clusters and the AFM matrix varies accordingly. Therefore, the magnetic ground states (corresponding to different compositions) of MSMAs play an important role in defining the EB properties.…”