Structural and magnetic properties of SmCo-based magnetic films grown by electron-beam evaporation

• Published in: Journal of magnetism and magnetic materials 2015-07, Vol.385, p.313-317
• Main Authors: Saravanan, P., Vinod, V.T.P., Černík, Miroslav, Vishnuraj, R., Arout Chelvane, J., Kamat, S.V., Hsu, Jen-Hwa
• Format: Article
• Language: English
• Subjects: Coercive force; Devices; E-beam evaporation; Evaporation; Magnetic properties; Magnetic thin films; Magnetization; Phase composition; Silicon substrates; Sm–Co; Thick films
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2015.03.034

Sub-micron thick Sm–Co films (200 and 300nm) with selective phase composition are grown on Si (100) substrates by electron-beam evaporation using Sm-lean alloy targets such as Sm4Co96 and Sm8Co92. The structural and magnetic properties of Sm–Co films are characterized by x-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and super-conducting quantum interference device (SQUID) magnetometer. The Sm–Co films obtained with the Sm4Co96 target exhibit Sm2Co17 as a prominent phase; while the films produced with the Sm8Co92 target show Sm2Co7 as a major phase. Both the Sm–Co films reveal granular morphology; however, the estimated grain size values are slightly lower in the case of Sm2Co7 films, irrespective of their thicknesses. Coercivity (Hc) values of 1.48 and 0.9kOe are achieved for the as-grown 200-nm thick Sm2Co17 and Sm2Co7-films. Temperature-dependent magnetization studies confirm that the demagnetization behaviors of these films are consistent with respect to the identified phase composition. Upon rapid thermal annealing, maximum Hc value of 8.4kOe is achieved for the 200nm thick Sm2Co17-films. As far as e-beam evaporated Sm–Co films are concerned, this Hc value is one of the best values reported so far. •Electron-beam evaporation was exploited to grow sub-μm thick Sm–Co films.•Sm2Co7 and Sm2Co17 magnetic phases were crystallized using Sm-lean alloy targets.•Both 200 and 300-nm thick Sm–Co films revealed distinct granular morphology.•Sm–Co films of lower thickness exhibited high Hc and low Ms and vice-versa.•Coercivity value of 8.4kOe achieved for the 200-nm thick Sm2Co17-films after RTA.