  The crystal structure and magnetoresponsive properties of Fe-doped MnCoGe
alloys have been investigated using x-ray diffraction (XRD) and magnetic
measurements. By alloying the Fe-containing isostructure compounds into MnCoGe,
a magnetostructural transition from paramagnetic austenite to ferromagnetic
martensite with large magnetization difference can be realized in a temperature
window between the Curie temperatures of the austenite and martensite,
resulting in magnetic-field-induced martensitic transformations and large
magnetic-entropy changes. A structural and magnetic phase diagram of Fe-doped
MnCoGe alloys has been proposed.
