Enhancement of ferromagnetism in carbon doped Fe2MnGa.

C-doped Fe 2 MnGaC x (x = 0, 0.05, 0.1 and 0.2) alloys have been synthesized and the influence of carbon on the structure and magnetic properties of Fe 2 MnGa has been investigated. The doping of C can expand the lattice of Fe 2 MnGa, suggesting that it enters the interstitial site of FCC lattice. The ferromagnetic coupling in Fe 2 MnGaC x can be strongly enhanced with increasing C content. The ferromagnetic to antiferromagnetic transition in undoped Fe 2 MnGa is suppressed by C-doping and disappears when x = 0.1 and 0.2. The saturation magnetization M s and Curie temperature T C also increase with C-doping. Large coercivity and exchange bias can be observed in the magnetic hysteresis loops of Fe 2 MnGa, due to the coexistence of FM and AFM states. But in Fe 2 MnGaC 0.2 , both of them disappear and a pure ferromagnetic character is observed. All this suggests that C-doping can be a possible way to adjust the magnetic properties of Fe 2 MnGa and other related alloys. • Fe 2 MnGaC x alloys were synthesized successfully. • Effect of C-doping on structure and magnetism of Fe 2 MnGa was studied. • Ferromagnetic state in Fe 2 MnGa can be strongly enhanced by C-doping. • A possible way to adjust the magnetic structure of Fe 2 MnGa is proposed. [ABSTRACT FROM AUTHOR]