Realization of metamagnetic martensitic transformation with multifunctional properties in Co50V34Ga16 Heusler alloy

Abstract

In this work, we have developed a ferromagnetic shape memory alloy Co50V34Ga16 with a metamagnetic martensitic transformation (MT) from the high-magnetization austenitic phase to the low-magnetization martensitic phase. As a consequence of a strong coupling between structure and magnetic degrees of freedom, the metamagnetic MT of this alloy is relatively sensitive to the external magnetic field, thus giving rise to a field-induced reverse MT. Associated with such a unique behavior, both considerable inverse magnetocaloric effect (9.6 J/kg K) and magnetostrain (0.07%) have also been obtained under the magnetic field change of 3 T. Our experimental results indicate that this kind of Co-V based alloy probably becomes an alternatively promising candidate for applications in magnetic sensors and magnetic refrigeration.

Large Elastocaloric Effect in Fe‐Doped Co–Fe–V–Ga Shape Memory Alloys

“…[21,22] In the past few decades, Co-based Heusler alloys have aroused wide concern as potential candidates for spintronic applications. [17,[23][24][25][26][27][28][29] Besides, the martensitic transformation (MT) in Co-based alloys has been under consideration since the 1970s. [28,30] In particular, the Co-based Heusler alloys undergoing the first-order type MT, namely the transformation from the L2 1 cubic austenitic structure to the D0 22 tetragonal martensitic structure, have been developed.…”

“…[17,[23][24][25][26][27][28][29] Besides, the martensitic transformation (MT) in Co-based alloys has been under consideration since the 1970s. [28,30] In particular, the Co-based Heusler alloys undergoing the first-order type MT, namely the transformation from the L2 1 cubic austenitic structure to the D0 22 tetragonal martensitic structure, have been developed. [17,28,31] Xu et al observed the MT in Co-V-Ga Heusler alloys throughout a wide temperature range from 250 to 500 K, and established the phase diagram depending on the alloy composition.…”

“…[28,30] In particular, the Co-based Heusler alloys undergoing the first-order type MT, namely the transformation from the L2 1 cubic austenitic structure to the D0 22 tetragonal martensitic structure, have been developed. [17,28,31] Xu et al observed the MT in Co-V-Ga Heusler alloys throughout a wide temperature range from 250 to 500 K, and established the phase diagram depending on the alloy composition. [31] Furthermore, the occurrence of MT has also been reported in off-stoichiometric or metal atom doped Co-based alloys, such as Co 2 Cr(Al, Si, Ga) [32] and Co 2 VGa 0.5 Sb 0.5 systems.…”

“…[23] Recently, a considerable entropy change (ΔS tra ) associated with a metamagnetic MT has been realized in Co 50 V 34 Ga 16 alloy via the control of MT temperatures and Curie temperature. [28] In addition, the substitution of Fe for Co has been conducted in the Co-V-Ga alloys to reduce the magnetization difference…”

“…[ 23 ] Recently, a considerable entropy change (Δ S tra ) associated with a metamagnetic MT has been realized in Co 50 V 34 Ga 16 alloy via the control of MT temperatures and Curie temperature. [ 28 ] In addition, the substitution of Fe for Co has been conducted in the Co–V–Ga alloys to reduce the magnetization difference (ΔM), affecting the magnetic entropy and MT temperatures and thereby increasing Δ S tra in those alloys. [ 23 ] In many ferromagnetic SMAs, Fe element doping is often used to adjust MT temperatures and mechanical properties, which are important parameters of the elastocaloric materials.…”