Effects of Co/Sm Composition on the Ordered Phase Formation in Sm-Co Thin Films Grown on Cu(111) Single-Crystal Underlayers
Sm-Co thin films were prepared on Cu(111) single-crystal underlayers by changing the Sm composition from 12 to 35 at.% and the effects of Co/Sm composition on the ordered phase formation were investigated. The epitaxial SmCo5 thin films were obtained for all samples. The SmCo5 epitaxial layer grown on Cu underlayer has two different types of domains whose orientations are rotated around film normal by 30 degrees to each other. Cu atoms substitute a part of the Co sites in the SmCo5 structure, and an alloy compound of Sm(Co,Cu) 5 phase was formed for all samples. The Sm(Co,Cu)5 phase was more Cu enriched with increasing the Sm composition. The Cu atom diffusion into Sm-Co layer plays an important role in assisting the formation of Sm(Co,Cu)5 ordered phase.
Sm(Co{sub 1−x}Ni{sub x}){sub 5} ordered alloy thin films formed on Cr(100) single-crystal underlayers
Sm{sub 17}(Co{sub 1−x}Ni{sub x}){sub 83} (at. %, x = 0, 0.2, 0.8, and 1) alloy thin films are deposited on Cr(100) single-crystal underlayers at temperatures ranging between 100 and 500 °C by molecular beam epitaxy. The effects of substrate temperature and Ni/Co composition on the film growth behavior and the detailed resulting structure are investigated. Formation of epitaxial RT{sub 5} (R: rare earth metal, T: transition metal) ordered crystals is, respectively, recognized for the films with x of 0, 0.2, 0.8, and 1 deposited at temperatures higher than 400, 400, 300, and 300 °C, whereas the films deposited below the respective temperatures consist of amorphous phases. The order degree increases with increasing the substrate temperature and the Ni content. The order degrees of films with x of 0, 0.2, 0.8, and 1 deposited at 500 °C are 0.6, 0.7, 0.8, and 0.9, respectively. A replacement of Co site in SmCo{sub 5} structure with Ni atom is useful for enhancing the formation of RT{sub 5} ordered phase.
Epitaxial growth and characterization of Y2Co17(0001) thin films deposited on W(110)
Y2Co17(0001) was grown on W(110) by pulsed laser deposition. The structural and morphological features of the films as a function of substrate temperature and thickness were studied in situ by means of reflection high‐energy electron diffraction, and ex situ by means of scanning electron microscopy, transmission electron microscopy, and x‐ray analysis (diffraction and reflection). Different growth modes were observed depending on the experimental conditions. They are discussed by considering the kinetical properties of the deposit and the thermodynamical properties of the system. The magnetic properties of the films have been investigated and related to the structural analysis.