**2. Experimental details**

The compositions of Ni50-xMn37+xSn13 (x = 0, 1, 2, 3, 4) alloys were prepared by arc melting technique under argon atmosphere. To ensure the homogeneity, the samples are re-melted four times. These alloys were annealed under high vacuum at 1175 K for 6 h and then quenched with Ar gas. The magnetic data were taken suing the physical property measurement system (PPMS-9 T)—vibrating sample magnetometer (VSM) module (Quantum Design, USA). The measurements were taken into two different modes which can be referred as ZFC and FC modes. The sample was firstly cooled in zero magnetic field, and the data was collected by applying a magnetic field of 5 mT during warming in the temperature range of 4–330 K. This refers to zero-field cooled (ZFC) mode. In field cooled (FC) mode, the data was collected without removing the applied field during cooling in the temperature range between 330 and 4 K. Again, the data was recorded upon warming in the range of 4–330 K (referred as field warming (FW)). Magnetization as a function of magnetic field was recorded up to a field of 5 T in the low temperatures.
