Separate magnetic and structural phase transitions in Mn_50−xFe_xRh₅₀ films grown on MgO

Abstract Investigations of the magnetic and structural characteristics of Mn 50− x Fe x Rh 50 alloys are important due to their notable phase transition behavior. In this study, a series of highly ordered epitaxial films with varying Fe concentrations are grown on MgO (001) substrate. At low Fe concentrations ( x = 0, 2, 6), a separation between the structural phase transition and the magnetic phase transition is observed. Unlike structural phase transitions, temperature-dependent magnetization exhibits fairly large temperature hysteresis. In addition, the structural transition induces further tetragonal distortion, resulting in an intermediate phase between the B2 and L1 0 structures. This separated magnetic and structural phase transitions have been further validated through x-ray diffraction, anisotropic magnetoresistance and spin-pumping measurements. Moreover, as the Fe concentration is increased, the Mn 50− x Fe x Rh 50 films exhibit ferromagnetic behavior due to competitive magnetic exchange interactions, while the structural phase transition is suppressed.