Effect of interfacial pinning on the thermo-remanent magnetization of disorder Mn50Ni38.5Sn11.5 alloy

• Unravels the low temperature magnetic character of this alloy.
• Role of field cooling on martensite magnetization.
• Large exchange bias effect and its slower temperature variation.
• Temperature independent nature of martensite resistivity.
• Large transition entropy and magnetoresistance.

In this report we show that field cooling through the irreversibility temperature (Tirr) only has more significant effect on the thermo-remanent magnetization (TRM) of martensite phase than the system cooled through its martensite transformation (MT). The large TRM observed at low temperature martensite phase is not associated with the arrest of higher magnetic austenite phase. The pinning of uncompensated spins at the interfaces of magnetically inhomogeneous phases is mainly contributing to the large irreversibility between the TRM curves. This strong pinning results to a huge exchange bias field (HEB)(HEB). A giant entropy change (ΔStrΔStr) of 18.1 J/kg K and a large negative magneto-resistance (MR) of 27% for field change (ΔHΔH) of 50 kOe are estimated across the MT. We have comprehensively discussed these observed behaviours in the paper.