Shih-Hung Lin , Yung-Huang Chang , Yuan-Tsung Chen , Xuan-Ming Su , Wen Chang , Huang-Wei Chang
{"title":"柔性基板上非晶Co40Fe40Gd20薄膜的机械、电学、磁学和光学性能受表面粗糙度的影响","authors":"Shih-Hung Lin , Yung-Huang Chang , Yuan-Tsung Chen , Xuan-Ming Su , Wen Chang , Huang-Wei Chang","doi":"10.1016/j.intermet.2025.109090","DOIUrl":null,"url":null,"abstract":"<div><div>Amorphous cobalt-iron-gadolinium (Co<sub>40</sub>Fe<sub>40</sub>Gd<sub>20</sub>) thin films with thicknesses of 10 nm–50 nm were deposited on flexible polyethylene terephthalate (PET) and polymethyl methacrylate (PMMA) substrates via direct-current (DC) magnetron sputtering and annealed at 40 °C and 80 °C to investigate the effects of film thickness, annealing temperature, and substrate type on structural, mechanical, electrical, magnetic, and optical properties. X-ray diffraction (XRD) confirmed the films remained amorphous under all conditions, due to the high gadolinium (Gd) content and limited thermal energy below the polymer glass transition temperatures. Atomic force microscopy (AFM) revealed substrate-dependent surface evolution, with PET films showing a decrease in roughness from 5.91 nm to 4.79 nm after 80 °C annealing, whereas PMMA films exhibited minimal roughness change. Surface energy increased with film thickness but decreased slightly upon annealing due to atomic rearrangement. Mechanical properties improved with both thickness and annealing. PET films reached a maximum Young's modulus of 22.58 GPa and hardness of 4.75 Gpa at 50 nm after 80 °C annealing, while PMMA films achieved 15.05 GPa modulus at 50 nm after 40 °C. Electrical measurements showed a significant reduction in sheet resistance from 7261 Ω/sq for as-deposited 10 nm films to 144 Ω/sq for 50 nm films annealed at 80 °C, with enhanced carrier mobility and concentration. Magnetic analysis confirmed in-plane soft magnetic behavior, with minor variations in coercivity (H<sub>c</sub>) and saturation magnetization (M<sub>s</sub>) influenced by stress relaxation and morphology-induced anisotropy. Magnetic force microscopy (MFM) indicated moderate annealing promoted ordered stripe domains, while higher temperatures induced domain coarsening. Optical characterization revealed transmittance decreased with thickness, reaching 40.68 % and 47.15 % at 10 nm on PET and PMMA at annealing 40 °C, whereas absorbance increased, indicating thickness-dominated optical behavior. These findings demonstrate that controlled annealing and thickness optimization enable precise tuning of surface roughness and multifunctional properties of CoFeGd amorphous films on flexible substrates, supporting their design for advanced flexible spintronic, electronic, and optoelectronic devices.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"189 ","pages":"Article 109090"},"PeriodicalIF":5.3000,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Role of surface roughness in governing the mechanical, electrical, magnetic, and optical properties of amorphous Co40Fe40Gd20 thin films on flexible substrates\",\"authors\":\"Shih-Hung Lin , Yung-Huang Chang , Yuan-Tsung Chen , Xuan-Ming Su , Wen Chang , Huang-Wei Chang\",\"doi\":\"10.1016/j.intermet.2025.109090\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Amorphous cobalt-iron-gadolinium (Co<sub>40</sub>Fe<sub>40</sub>Gd<sub>20</sub>) thin films with thicknesses of 10 nm–50 nm were deposited on flexible polyethylene terephthalate (PET) and polymethyl methacrylate (PMMA) substrates via direct-current (DC) magnetron sputtering and annealed at 40 °C and 80 °C to investigate the effects of film thickness, annealing temperature, and substrate type on structural, mechanical, electrical, magnetic, and optical properties. X-ray diffraction (XRD) confirmed the films remained amorphous under all conditions, due to the high gadolinium (Gd) content and limited thermal energy below the polymer glass transition temperatures. Atomic force microscopy (AFM) revealed substrate-dependent surface evolution, with PET films showing a decrease in roughness from 5.91 nm to 4.79 nm after 80 °C annealing, whereas PMMA films exhibited minimal roughness change. Surface energy increased with film thickness but decreased slightly upon annealing due to atomic rearrangement. Mechanical properties improved with both thickness and annealing. PET films reached a maximum Young's modulus of 22.58 GPa and hardness of 4.75 Gpa at 50 nm after 80 °C annealing, while PMMA films achieved 15.05 GPa modulus at 50 nm after 40 °C. Electrical measurements showed a significant reduction in sheet resistance from 7261 Ω/sq for as-deposited 10 nm films to 144 Ω/sq for 50 nm films annealed at 80 °C, with enhanced carrier mobility and concentration. Magnetic analysis confirmed in-plane soft magnetic behavior, with minor variations in coercivity (H<sub>c</sub>) and saturation magnetization (M<sub>s</sub>) influenced by stress relaxation and morphology-induced anisotropy. Magnetic force microscopy (MFM) indicated moderate annealing promoted ordered stripe domains, while higher temperatures induced domain coarsening. Optical characterization revealed transmittance decreased with thickness, reaching 40.68 % and 47.15 % at 10 nm on PET and PMMA at annealing 40 °C, whereas absorbance increased, indicating thickness-dominated optical behavior. These findings demonstrate that controlled annealing and thickness optimization enable precise tuning of surface roughness and multifunctional properties of CoFeGd amorphous films on flexible substrates, supporting their design for advanced flexible spintronic, electronic, and optoelectronic devices.</div></div>\",\"PeriodicalId\":331,\"journal\":{\"name\":\"Intermetallics\",\"volume\":\"189 \",\"pages\":\"Article 109090\"},\"PeriodicalIF\":5.3000,\"publicationDate\":\"2026-02-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Intermetallics\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0966979525004558\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2025/12/6 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Intermetallics","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0966979525004558","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/12/6 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Role of surface roughness in governing the mechanical, electrical, magnetic, and optical properties of amorphous Co40Fe40Gd20 thin films on flexible substrates
Amorphous cobalt-iron-gadolinium (Co40Fe40Gd20) thin films with thicknesses of 10 nm–50 nm were deposited on flexible polyethylene terephthalate (PET) and polymethyl methacrylate (PMMA) substrates via direct-current (DC) magnetron sputtering and annealed at 40 °C and 80 °C to investigate the effects of film thickness, annealing temperature, and substrate type on structural, mechanical, electrical, magnetic, and optical properties. X-ray diffraction (XRD) confirmed the films remained amorphous under all conditions, due to the high gadolinium (Gd) content and limited thermal energy below the polymer glass transition temperatures. Atomic force microscopy (AFM) revealed substrate-dependent surface evolution, with PET films showing a decrease in roughness from 5.91 nm to 4.79 nm after 80 °C annealing, whereas PMMA films exhibited minimal roughness change. Surface energy increased with film thickness but decreased slightly upon annealing due to atomic rearrangement. Mechanical properties improved with both thickness and annealing. PET films reached a maximum Young's modulus of 22.58 GPa and hardness of 4.75 Gpa at 50 nm after 80 °C annealing, while PMMA films achieved 15.05 GPa modulus at 50 nm after 40 °C. Electrical measurements showed a significant reduction in sheet resistance from 7261 Ω/sq for as-deposited 10 nm films to 144 Ω/sq for 50 nm films annealed at 80 °C, with enhanced carrier mobility and concentration. Magnetic analysis confirmed in-plane soft magnetic behavior, with minor variations in coercivity (Hc) and saturation magnetization (Ms) influenced by stress relaxation and morphology-induced anisotropy. Magnetic force microscopy (MFM) indicated moderate annealing promoted ordered stripe domains, while higher temperatures induced domain coarsening. Optical characterization revealed transmittance decreased with thickness, reaching 40.68 % and 47.15 % at 10 nm on PET and PMMA at annealing 40 °C, whereas absorbance increased, indicating thickness-dominated optical behavior. These findings demonstrate that controlled annealing and thickness optimization enable precise tuning of surface roughness and multifunctional properties of CoFeGd amorphous films on flexible substrates, supporting their design for advanced flexible spintronic, electronic, and optoelectronic devices.
期刊介绍:
This journal is a platform for publishing innovative research and overviews for advancing our understanding of the structure, property, and functionality of complex metallic alloys, including intermetallics, metallic glasses, and high entropy alloys.
The journal reports the science and engineering of metallic materials in the following aspects:
Theories and experiments which address the relationship between property and structure in all length scales.
Physical modeling and numerical simulations which provide a comprehensive understanding of experimental observations.
Stimulated methodologies to characterize the structure and chemistry of materials that correlate the properties.
Technological applications resulting from the understanding of property-structure relationship in materials.
Novel and cutting-edge results warranting rapid communication.
The journal also publishes special issues on selected topics and overviews by invitation only.