Structural and magnetic properties of FexSey thin films during their selenization process

Abstract

Fe x Se y films were prepared on GaAs(001) substrates by a selenization of Fe films using molecular beam epitaxy equipment. Structural and magnetic properties of FexSey thin films during their selenization process were studied. The selenized films obtained consisted of polycrystalline grains of 100–700 nm. A magnetic anisotropy of in-plane/perpendicular to the films was weakened by increasing the selenization ratio of the samples, which was interesting in contrast to the fact that the grain size of the films became larger.

Growth of FeSe on general substrates by metal-organic chemical vapor deposition and the application in magnet tunnel junction devices

“…Selenization of iron thin films is an usual route to fabricate Fe-Se compounds thin films. However, it usually obtains non-oriented thin films, even mixtures of more than two Fe-Se compounds [5][6][7][8]. The unsatisfactory crystal quality limits the study on Fe-Se compounds within composition analysis and structure characterization, and accordingly restricts the research on optical, electrical properties.…”

High oriented FeSe thin film on GaAs(100) substrate prepared by low-pressure metalorganic chemical vapor deposition

“…Characterizations of bulk crystals of FeSe have been reported with Fe 3 Se 4 and Fe 7 Se 8 structures [11,12]. Furthermore, FeSe is preferably replaced by selenization technique [8,13,14], the selenization was performed with supplying a Se beam to the Fe films on GaAs substrate. But FeSe thin films have not been studied much, which especially prepared by MOCVD method.…”

On the nature of the carriers in ferromagnetic FeSe

“…Bulk Fe 7 Se 8 and Fe 3 Se 4 , of which the lattice structure is NiAs type with ordered Fe vacancies, have shown Curie temperatures of 314 and 455 K, respectively. 3,4 Most interestingly, FeSe is claimed to be a semiconductor with a band gap of either 3.0 ͑Refs. 5 and 6͒ or 0.14 eV, 7 though no enough convincing experimental evidences are available.…”