Control of Structural and Magnetic Properties of Polycrystalline Co₂FeGe Films via Deposition and Annealing Temperatures

• Main Authors: Andrii Vovk, Sergey A. Bunyaev, Pavel Štrichovanec, Nikolay R. Vovk, Bogdan Postolnyi, Arlete Apolinario, José Ángel Pardo, Pedro Antonio Algarabel, Gleb N. Kakazei, João Pedro Araujo
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: Nanomaterials
• Subjects: thin films; Heusler alloys; magnetostatic properties; Ferromagnetic resonance
• Online Access: https://www.mdpi.com/2079-4991/11/5/1229
• ISSN: 2079-4991

Thin polycrystalline Co₂FeGe films with composition close to stoichiometry have been fabricated using magnetron co-sputtering technique. Effects of substrate temperature (T_S) and post-deposition annealing (T_a) on structure, static and dynamic magnetic properties were systematically studied. It is shown that elevated T_S (T_a) promote formation of ordered L2₁ crystal structure. Variation of T_S (T_a) allow modification of magnetic properties in a broad range. Saturation magnetization ~920 emu/cm³ and low magnetization damping parameter α ~ 0.004 were achieved for T_S = 573 K. This in combination with soft ferromagnetic properties (coercivity below 6 Oe) makes the films attractive candidates for spin-transfer torque and magnonic devices.