Structural, Magnetic, and Magnetocaloric Studies of Ball-Milled Fe100-xTx (T = Ni and Mn) Alloy

Iron-transition metal-based binary and ternary alloys have attracted great attention due to their relevant mechanical, electrical, and magnetic properties. In this paper, we systematically investigate the structural, magnetic, and magnetocaloric behavior of as-milled Fe65T35 (T = Ni and Mn) alloy. The polycrystalline alloys were produced by the planetary ball milling, using a powder-to-ball ratio of 1:3. A structural study reveals that both Fe65Ni35 and Fe65Mn35 compounds have stabilized in alpha and gamma mixed phase within the cubic crystal structure. The alloyed compounds are further characterized by high-resolution field emission scanning electron microscopy (HR-FESEM), which confirms the mixing of both metals in the alloying process. Temperature-dependent magnetic studies do not show any blocking in zero-field-cooled and field-cooled results; however, the field-dependent magnetization study demonstrates the ferromagnetic nature with small hysteresis in both compounds. Both compounds show a significant magnetocaloric effect over a wide temperature range around room temperature. Fe65Ni35 exhibit a slightly higher value in comparison to Fe65Mn35. In both the alloys, magnetic entropy change follows the power law behavior against the external magnetic field, and the value of exponent 'm' explains the presence of magnetic correlation. Our investigation in this study communicates that the phase control or coexistence of both phases may be efficacious in obtaining the desirable characteristic of magnetic and magnetocaloric demeanors in such a binary Fe-T alloy.