Abstract
Strain effects in epitaxial films can substantially enhance individual functional properties or induce properties which do not exist in corresponding bulk materials. The bcc α-Fe50Mn50 films are a ferromagnetic with a Curie temperature between 650 K and 750 K, which do not exist in nature can be manipulated through the tensile strain. In this study, γ-Fe50Mn50 epitaxial films grown on GaAs(001) using molecular beam epitaxy are found to structural transition from the face-centered-cubic (fcc, a = 0.327 nm) γ-phase to the body-centered-cubic (bcc, a = 0.889 nm) α-phase. For α-Fe50Mn50 epitaxial films, ferromagnetism is accompanied by structural phase transition due to the tensile strain induced by the differences of the thermal expansion between the film and the substrate. Moreover, by realizing in epitaxial films with fcc structure a tensile strain state, phase transitions were introduced Fe-Mn alloy system with bcc structure. These findings are of fundamental importance to understanding the mechanism of phase transition and properties of epitaxial CuAu-I type antiferromagnetic alloy thin films under strain.
Highlights
In the recent years, most of the paradigmatic concepts used in spintronics have been replicated substituting ferromagnets by antiferromagnets in critical parts of the devices[1,2,3]
Antiferromagnetic-based magnetic storage devices such as spin-valve structures and magnetic tunnel junctions have been widely investigated in the emerging field of spintronics, in which the antiferromagnets provide pinning for a reference ferromagnetic layer due to an interfacial effect called an exchange bias[7,8]
For metallic antiferromagnetic materials which play an irreplaceable role in traditional spintronic devices, direct electrical control remains challenging because of the screening effect by the surface charge
Summary
Most of the paradigmatic concepts used in spintronics have been replicated substituting ferromagnets by antiferromagnets in critical parts of the devices[1,2,3]. The discovery of electrical switching of metallic antiferromagnets by spin-orbital torque has provided an example that the antiferromagnetic moment can be controlled more efficiently in a microelectronic device compared to a ferromagnetic material[11,12]. Γ-Fe50Mn50 layers exhibit spin-Hall magnetoresistance and large inverse spin-Hall effect voltage, implying that the antiferromagnetic materials can be both spin current detector and generator[19,20,21] These investigations open up new opportunities in developing the antiferromagnetic based spintronic devices. In order to induce artificial strain on epitaxial thin films, we focus on the structural and the magnetic phase transitions of CuAu-I type γ-Fe100−xMnx alloys for efficient and tunable electrical manipulation of ferromagnetic materials. Our experimentally magnetic phase transition was shown to be accompanied by structural phase transition, it is dominated by the epitaxial strain effect from the substrates
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
