A systematic study of the antiferromagnetic-ferromagnetic conversion and competition in MnNiGe:Fe ribbon systems

MnNiGe:Fe ribbon samples are prepared. Partial Ni- and Mn-substitution of Fe element can both induce the antiferromagnetic-ferromagnetic conversion in the TiNiSi-type state of these MnNiGe:Fe ribbon systems. It is found out, however, that some factors such as annealing, temperature variation process, field-cycling, substituted site and magnetic field can affect the conversion and competition between the antiferromagnetic and ferromagnetic states in these ribbons. Therefore, in this paper these major influencing factors are studied systematically and further discussed are the related magnetic and magnetocaloric properties in MnNiGe:Fe ribbon systems.