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Vovk A, Popadiuk D, Postolnyi B, Bunyaev S, Štrichovanec P, Pardo JÁ, Algarabel PA, Salyuk O, Korenivski V, Kakazei GN, Golub VO, Araujo JP. Effect of Thermal Processing on the Structural and Magnetic Properties of Epitaxial Co 2FeGe Films. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:1745. [PMID: 39513825 PMCID: PMC11547484 DOI: 10.3390/nano14211745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2024] [Revised: 10/27/2024] [Accepted: 10/29/2024] [Indexed: 11/16/2024]
Abstract
The structure and magnetic properties of epitaxial Heusler alloy films (Co2FeGe) deposited on MgO (100) substrates were investigated. Films of 60 nm thickness were prepared by magnetron co-sputtering at different substrate temperatures (TS), and those deposited at room temperature were later annealed at various temperatures (Ta). X-ray diffraction confirmed (001) [110] Co2FeGe || (001) [100] MgO epitaxial growth. A slight tetragonal distortion of the film cubic structure was found in all samples due to the tensile stress induced by the mismatch of the lattice parameters between Co2FeGe and the substrate. Improved quality of epitaxy and the formation of an atomically ordered L21 structure were observed for films processed at elevated temperatures. The values of magnetization increased with increasing TS and Ta. Ferromagnetic resonance (FMR) studies revealed 45° in-plane rotation of the easy anisotropy axis direction depending on the degree of the tetragonal distortion. The film annealed at Ta = 573 K possesses the minimal FMR linewidth and magnetic damping, while both these parameters increase for another TS and Ta. Overall, this study underscores the crucial role of thermal treatment in optimizing the magnetic properties of Co2FeGe films for potential spintronic and magnonic applications.
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Affiliation(s)
- Andrii Vovk
- Institute of Physics for Advanced Materials, Nanotechnology and Photonics (IFIMUP), Departamento de Fisica e Astronomia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal; (B.P.); (S.B.); (G.N.K.); (J.P.A.)
| | - Dariia Popadiuk
- Nanostructure Physics, Royal Institute of Technology, 10691 Stockholm, Sweden; (D.P.); (V.K.)
- Institute of Magnetism National Academy of Sciences of Ukraine and Ministry of Education and Science of Ukraine, 36-B Vernadsky Blvd., 03142 Kyiv, Ukraine; (O.S.); (V.O.G.)
- Institute of Spintronics and Quantum Information, Faculty of Physics Adam, Mickiewicz University, 61-712 Poznan, Poland
| | - Bogdan Postolnyi
- Institute of Physics for Advanced Materials, Nanotechnology and Photonics (IFIMUP), Departamento de Fisica e Astronomia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal; (B.P.); (S.B.); (G.N.K.); (J.P.A.)
- Department of Nanoelectronics and Surface Modification, Sumy State University, 40007 Sumy, Ukraine
| | - Sergey Bunyaev
- Institute of Physics for Advanced Materials, Nanotechnology and Photonics (IFIMUP), Departamento de Fisica e Astronomia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal; (B.P.); (S.B.); (G.N.K.); (J.P.A.)
| | - Pavel Štrichovanec
- Instituto de Nanociencia y Materiales de Aragón, Universidad de Zaragoza—CSIC, Campus Río Ebro, 50018 Zaragoza, Spain; (P.Š.); (J.Á.P.); (P.A.A.)
| | - José Ángel Pardo
- Instituto de Nanociencia y Materiales de Aragón, Universidad de Zaragoza—CSIC, Campus Río Ebro, 50018 Zaragoza, Spain; (P.Š.); (J.Á.P.); (P.A.A.)
- Departamento de Ciencia y Tecnología de Materiales y Fluidos, Universidad de Zaragoza, 50018 Zaragoza, Spain
| | - Pedro Antonio Algarabel
- Instituto de Nanociencia y Materiales de Aragón, Universidad de Zaragoza—CSIC, Campus Río Ebro, 50018 Zaragoza, Spain; (P.Š.); (J.Á.P.); (P.A.A.)
- Instituto de Nanociencia y Materiales de Aragón, Universidad de Zaragoza—CSIC, Campus San Francisco, 50009 Zaragoza, Spain
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - Olga Salyuk
- Institute of Magnetism National Academy of Sciences of Ukraine and Ministry of Education and Science of Ukraine, 36-B Vernadsky Blvd., 03142 Kyiv, Ukraine; (O.S.); (V.O.G.)
| | - Vladislav Korenivski
- Nanostructure Physics, Royal Institute of Technology, 10691 Stockholm, Sweden; (D.P.); (V.K.)
| | - Gleb N. Kakazei
- Institute of Physics for Advanced Materials, Nanotechnology and Photonics (IFIMUP), Departamento de Fisica e Astronomia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal; (B.P.); (S.B.); (G.N.K.); (J.P.A.)
| | - Vladimir O. Golub
- Institute of Magnetism National Academy of Sciences of Ukraine and Ministry of Education and Science of Ukraine, 36-B Vernadsky Blvd., 03142 Kyiv, Ukraine; (O.S.); (V.O.G.)
| | - João Pedro Araujo
- Institute of Physics for Advanced Materials, Nanotechnology and Photonics (IFIMUP), Departamento de Fisica e Astronomia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal; (B.P.); (S.B.); (G.N.K.); (J.P.A.)
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Mao M, Ke S, Tang D, Sang X, He D. Structure and Performance Optimization of Co Magnetic Thin Films Deposited by Vacuum Evaporation Coating. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16093395. [PMID: 37176276 PMCID: PMC10179819 DOI: 10.3390/ma16093395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 04/19/2023] [Accepted: 04/20/2023] [Indexed: 05/15/2023]
Abstract
Co magnetic films are widely used in high-frequency magnetic recording and vertical magnetic recording due to their high saturation magnetization and magnetocrystalline anisotropy. In this work, ferromagnetic Co magnetic films were prepared on copper substrate by vacuum evaporation combined with heat treatment (H2 atmosphere), to investigate the impact of film thickness and annealing temperature on microstructure and magnetic properties. The results show that with the increase in annealing temperature, the Co thin film physical phase does not change significantly, the crystallinity increases, and the grain size increases, which is consistent with the results obtained from the SEM morphology map of the sample surface, leading to an increase in coercivity. By annealing experiments (atmospheric atmosphere) on Co magnetic films with and without an Al protective layer, as shown by scanning electron microscopy microscopic characterization results, it was verified that the Al layer can protect the inner Co layer from oxidation. As the film thickness increases from 10 to 300 nm, the magnetic properties of Co films change significantly. The saturation magnetization gradually increases from 0.89 to 5.21 emu/g, and the coercivity increases from 124.3 to 363.8 Oe. The remanence ratio of the 10 nm magnetic film is 0.82, which is much higher than the film remanence ratio of 0.46 at 50 nm. This is because when the thickness of the film is between 10 and 50 nm, the magnetic moments partially deviate from the in-plane direction, and the out-of-plane component reduces the film remanence ratio. This study shows that optimizing annealing temperature and film thickness can effectively control the structure and magnetic properties of Co magnetic films, which is of great significance for the development of the magnetic recording field.
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Affiliation(s)
- Mingheng Mao
- State Key Laboratory of New Materials and Composites Technology, Wuhan University of Technology, Wuhan 430070, China
| | - Shaoqiu Ke
- State Key Laboratory of New Materials and Composites Technology, Wuhan University of Technology, Wuhan 430070, China
| | - Dingguo Tang
- School of Chemistry and Materials Science, Central South University for Nationalities, Wuhan 430074, China
| | - Xiahan Sang
- State Key Laboratory of New Materials and Composites Technology, Wuhan University of Technology, Wuhan 430070, China
| | - Danqi He
- State Key Laboratory of New Materials and Composites Technology, Wuhan University of Technology, Wuhan 430070, China
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