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Bilayer is an effective structure to enhance magnetic properties of films. This study employs high magnetic field (HMF) and amorphous Fe–Sm under-layer to tune the magnetic properties of evaporated Co–Sm/Fe–Sm bilayer films. Various analysis methods are used to explore the relation of microstructure evolution under above conditions with magnetic performance. The results show that both the amorphous Fe–Sm under-layer and the HMF can decrease surface roughness. Further, the HMF exhibits other effects that reduces column size, increases interplanar spacing and affects interface at atomic scale. The structural variation has effect on magnetic properties of bilayer films. The amorphous Fe–Sm under-layer increases magnetization, coercivity and squareness through changing the amount of non-magnetic structure at atomic scale. Meanwhile, the HMF decreases coercivity by changing pinning via the interface variation. Both the HMF and amorphous under-layer have no influence on the anisotropy of bilayer films. These results present an effective method to tune the magnetic properties of films through amorphous under-layer and HMF. • Amorphous FeSm under-layer has effect on microstructure and magnetic performance. • High magnetic field improves magnetization by affecting non-magnetic structure. • High magnetic field decreases coercivity by changing interface pinning. • Effect of high magnetic field on squareness is smaller than that of amorphous layer. [ABSTRACT FROM AUTHOR]

Huge difference of surface energies between dielectric and metal provides an effective method to tune the structure and magnetic properties of films. Due to the difference of surface energies between SiO 2 and Fe, dopant of SiO 2 with 3.6% in atomic ratio in Fe film transforms the strip and column structure in the Fe films to equiaxed crystal formed by nanoparticles of the Fe-SiO 2 films. Zeeman energy of applying high magnetic field (HMF) during film growth increases Fe atomic aggregation and atomic diffusion of SiO 2 into the grain boundary. This leads to the improvement of the particle size with applying HMF during the film growth. These structural evolutions have a significant effect on the performance of the films. After the dopant of SiO 2 , the saturation magnetization M s of the Fe-SiO 2 film (324.6 kA/m) is 73.2% less than that of the Fe films. The coercivity H c decreases 204.0% to 788.04 A/m. However, the M s increases 44.3% and the H c increases 27.4% for the Fe-SiO 2 film with applying HMF during the film growth. [ABSTRACT FROM AUTHOR]

This paper studies the effects of high magnetic field (HMF) on the structure, optical and thermoelectric properties of the doped ZnO thin films. The results show that both Al dopant and application of HMF can affect the crystal structure, surface morphology, elemental distribution and so on. The particles of the thin films become small and regular by doping Al. The ZnO films oxidized from the Au/Zn bilayer have needle structure. The ZnO films oxidized from the Au/Zn-Al bilayer transform to spherical from hexagonal due to the application of HMF. The transmittance decreases with doping Al because of the opaque of Al element and decreases with the application of HMF due to the dense structure obtained under HMF. Electrical resistivity ( ρ ) of the ZnO films without Al decreases with increasing measurement temperature ( T ) and is about 1.5 × 10 −3 Ω·m at 210 °C. However, the ρ of the Al-doped ZnO films is less than 10 −5 Ω·m. The Seebeck coefficient ( S ) of the films oxidized from the Au/Zn-Al films reduces with increasing T . The S values oxidized under 0 T and 12 T conditions are 2.439 μV/K and −3.415 μV/K at 210 °C, respectively. Power factor reaches the maximum value (3.198 × 10 −4 W/m·K 2 ) at 210 °C for the film oxidized under 12 T condition. These results indicate that the Al dopant and the application of HMF can be used to control structure and thermoelectric properties of doped ZnO films. [ABSTRACT FROM AUTHOR]

Microstructures and native defects are very important for the optical, electrical and magnetic properties of ZnO-based materials. In this study, microstructures of the Cu-doped ZnO (ZnO:Cu) films were changed by applying high magnetic field (HMF) during different growth processes of the as-deposited Zn-Cu films and the subsequent thermal oxidation treatment. The effects of the microstructure evolutions on the defects formation and photoluminescence performance are examined. The results show that the interaction between magnetization and thermal motion promotes (002) preferred orientation of the as-deposited Zn-Cu films. Meanwhile, the variation of the atomic deposition sites due to the HMF leads to the significant differences of surface morphology of the as-deposited films. The application of the HMF during the oxidation affects the adsorption sites of O 2− and leads the surface spherical particles change to rod-like particles. Moreover, the HMF shows more significant effects during the deposition of the Zn-Cu films in enhancing on the amount of the oxygen vacancy, which improves green emission of the ZnO:Cu films. [ABSTRACT FROM AUTHOR]

Sb-doped ZnO thermoelectric films with microporous structures are fabricated by oxidizing evaporated Zn-Sb thin films in a leaf-like surface. High magnetic field (HMF) and Sb are employed to tune the formation of nanowires and nanorods in the microporous films and conduction type. Nanowire is formed in the film with Sb content of 3.0% and nanorod is formed with 4.6% Sb with the absence of HMF. P-type ZnO films with a wuterzite are formed. The resistivity of the films decreases by two orders of magnitude by increasing Sb content. The resistivity of films decreases 45% and 80% by forming nanowires and nanorods, respectively. The power factor of the nanorod structures increases by two orders of magnitude by comparison with others and reaches to 52.6 μW/m K 2 . This indicates that the nanorod structures with a higher Sb content are easy to obtain stable p -type semiconductor with a higher power factor. [ABSTRACT FROM AUTHOR]

• Annealing and high magnetic fields (HMFs) adjusted growth structure of Fe films. • Different-stage HMFs and annealing suppressed strain and roughness of Fe films. • 10% larger M s than Fe bulk was obtained by combined film-growth HMF and annealing. • HMF and annealing decreased coercivity but increased remanence ratio of Fe films. • Film-growth HMF and annealing effectively adjust structure and improve properties. To improve the magnetic properties of films applied in spintronic devices, this article explored the microstructure and magnetic properties of Fe nanocrystalline films via annealing and applying high magnetic field (HMF) during different film-formation stages. The results indicate that both annealing and HMF inhibited the sloping and overlapping of the columnar grains in the as-deposited film. Annealing promoted the formation of nanoparticles, while annealing with HMF arrayed the columnar grains along the direction of HMF. A chain arrangement with mixture columnar grains and nanoparticles was observed by combined film-growth HMF and annealing. Different-stage HMFs and annealing improved the particle size but suppressed the stain and surface roughness of the Fe films. The film-growth HMF and annealing both enhanced the saturation magnetization (M s) of the Fe films. Especially, combined film-growth HMF and annealing obtained 10% larger M s than Fe bulk. The low disordered structure, average grain size and grain shape anisotropy under film-growth HMF and annealing remarkably decreased the coercivity (by 91%) but increased the remanence ratio (by 67%) of films. However, annealing with HMF did not obviously improve the magnetic properties of Fe films. These indicated that film-growth HMF and annealing provide useful ways to adjust structure and enhance properties. [ABSTRACT FROM AUTHOR]