화학공학소재연구정보센터
Applied Surface Science, Vol.346, 284-290, 2015
Low-frequency alternative-current magnetic susceptibility, photoelectric properties, and adhesive properties of Ni80Fe20 (X angstrom)/ZnO(500 angstrom) and ZnO(500 angstrom)/Ni80Fe20(Y angstrom) on glass substrate
The following conditions are deposited: (a) glass/Ni80Fe20(X angstrom)/ZnO(500 angstrom) and (b) glass/ZnO(500 angstrom)/Ni80Fe20(Y angstrom), where each of X and Y is 1000 angstrom, 1500 angstrom, 2000 angstrom or 2500 angstrom. The substrate temperature was maintained at room temperature (RT), and post-annealing was performed with heating at (T-A) = 150 degrees C for 1 h or (T-A) = 250 degrees C for 1 h. The sputtering sequence and the thickness of the NiFe film were varied to study the effects of these factors on the low-frequency alternative-current magnetic susceptibility (chi(ac)), maximum chi(ac) with corresponding optimal resonance frequency (f(res)), transmission, electrical resistivity (rho), and surface energy of the multilayered glass/Ni80Fe20(X angstrom)/ZnO(500 angstrom) and glass/ZnO(500 angstrom)/Ni80Fe20(Y angstrom). Experimental results demonstrate that ZnO(500 angstrom)/Ni80Fe20(Y angstrom) is superior to Ni80Fe20/ZnO(500 angstrom) because diffraction from the ZnO (0 0 2) crystals at the bottom of ZnO(500 angstrom)/Ni80Fe20(Y angstrom) improves the magneto crystalline anisotropy of Ni80Fe20, improving its magnetic and photoelectrical properties. X-ray diffraction patterns (XRD) reveal that the ZnO (0 0 2), ZnO (2 2 0), and NiFe (1 1 1) peaks of ZnO(500 angstrom)/Ni80Fe20(Y angstrom) are more intense than those of Ni80Fe20/ZnO(500 angstrom) under three substrate conditions, indicating the ZnO (0 0 2) peak reflects magneto crystalline anisotropy in the crystalline NiFe layer of ZnO(500 angstrom)/Ni80Fe20(Y angstrom), yielding the highest chi(ac) of approximately 3.16 with an fres of 250 Hz upon post-annealing T-A = 250 degrees C for 1 h. The (1 1 1) diffracted intensity and grain size of the thicker and post-annealed Ni80Fe20 thin films exceeded those of the thinner and as-deposited Ni80Fe20 thin films. A spectral analyzer was used to measure transmittance through NiFe of various thicknesses. The transmittance declined slightly as the thickness and grain size increased, because increasing thickness reduced penetration. Post-annealing promoted grain growth, increased the average size of the grains and reduced transmittance. Both as-deposited glass/Ni80Fe20(X angstrom)/ZnO(500 angstrom) and as-deposited glass/ZnO(500 angstrom)/Ni80Fe20(Y angstrom) had the highest penetration, when X, Y = 1000 angstrom, and the highest transmittances of 87% and 93%, respectively. The highest transmittance of glass/ZnO(500 angstrom)/Ni80Fe20(Y angstrom) exceeded that of glass/Ni80Fe20(X angstrom)/ZnO(500 angstrom) owing to ZnO (0 0 2) crystallization. Furthermore, rho decreased as the Ni80Fe20 thickness increased, because grain boundaries and the surface of thin films scattered the electrons, so thinner films had greater resistance. Electrical measurements revealed that the maximum resistivities of glass/Ni80Fe20(1000 angstrom)/ZnO(500 angstrom) and glass/ZnO(500 angstrom)/Ni80Fe20(1000 angstrom) were 292 mu Omega cm and 288 mu Omega cm, and the resistivity declined as the thickness of the film increased. The surface energy of the as-deposited and thinner NiFe layers exceeded that of post-annealed and thicker NiFe layers, revealing that the adhesion of the as-deposited and thinner NiFe films was stronger than that of the post-annealed and thicker films, on account of the degrees of crystallinity. Glass/Ni80Fe20(1000 angstrom)/ZnO(500 angstrom) and glass/ZnO(500 angstrom)/Ni80Fe20(1000 angstrom) had the highest surface energies of 64 mJ/mm2 and 59 mJ/mm(2); the surface energy worsened as the temperature increased, suggesting that the adhesion of the as-deposited and thinner NiFe films in glass/Ni80Fe20(X angstrom)/ZnO(500 angstrom) was stronger than in glass/ZnO(500 angstrom)/Ni80Fe20(Y angstrom). The results indicate that the magnetic and photoelectric properties of glass/ZnO(500 angstrom)/Ni80Fe20(Y angstrom) were better than those of glass/Ni80Fe20(X angstrom)/ZnO(500 angstrom) because the strong ZnO (0 0 2) crystallization in ZnO(500 angstrom)/Ni80Fe20(Y angstrom) increased the magneto crystalline anisotropy NiFe (1 1 1) and importantly affected the magnetic and photoelectrical properties. (C) 2015 Elsevier B.V. All rights reserved.