Large magnetocaloric effect and magnetoresistance in Fe-Co doped Ni50-x (FeCo)(x)Mn37Ti13 all-d-metal Heusler alloys

The effect of substituting FeCo in Ni site maintaining their same ratio on structural, magnetocaloric, and magneto-transport properties of all-d-metal Ni50-x(FeCo)(x)Mn37Ti13 (x = 16, 18, and 20) Heusler alloys are investigated. These alloys undergo a first-order magnetostructural transition (MST) between low temperature weak magnetic martensite (monoclinic or orthorhombic structure) to a high temperature ferromagnetic (FM) austenite (cubic structure) phase around room temperature. The MST temperature is observed to shift towards the lower temperature with increasing (FeCo)(x) content. These alloys with x = 16, 18, and 20 exhibit isothermal magnetic entropy change ( increment SM) as large as about similar to 13.8, similar to 12.7 and similar to 11.8 JkgK(-1) across their MST associated with an effective refrigerant capacity (RCeff) of about 119.9, similar to 126.2 and similar to 194.4 J/ kg respectively due to an application of 5 T magnetic field. It is interesting to note that increment SM remains almost identical over a large temperature region with (FeCo)(x) content from 16 to 20 at%. In addition, the maximum values of large magnetoresistance (MR)similar to 26.1% for x = 16, 25.4% for x = 18, and 24.3% for x = 20 are achieved at the field of 5 T. These materials with large magnetocaloric response in an extended temperature window around room temperature as well as large negative MR can be considered as potential candidates for multifunctional application. (c) 2022 Elsevier B.V. All rights reserved.