Low-frequency alternative-current magnetic susceptibility, photoelectric properties, and adhesive properties of Ni80Fe20 (XÅ)/ZnO(500Å) and ZnO(500Å)/Ni80Fe20(YÅ) on glass substrate
Abstract The following conditions are deposited: (a) glass/Ni 80 Fe 20 (XA)/ZnO(500A) and (b) glass/ZnO(500A)/Ni 80 Fe 20 (YA), where each of X and Y is 1000A, 1500A, 2000A or 2500A. The substrate temperature was maintained at room temperature (RT), and post-annealing was performed with heating at ( T A ) = 150 °C for 1 h or ( T A ) = 250 °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 ( χ ac ), maximum χ ac with corresponding optimal resonance frequency ( f res ), transmission, electrical resistivity ( ρ ), and surface energy of the multilayered glass/Ni 80 Fe 20 (XA)/ZnO(500A) and glass/ZnO(500A)/Ni 80 Fe 20 (YA). Experimental results demonstrate that ZnO(500A)/Ni 80 Fe 20 (YA) is superior to Ni 80 Fe 20 /ZnO(500A) because diffraction from the ZnO (0 0 2) crystals at the bottom of ZnO(500A)/Ni 80 Fe 20 (YA) improves the magneto crystalline anisotropy of Ni 80 Fe 20 , 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(500A)/Ni 80 Fe 20 (YA) are more intense than those of Ni 80 Fe 20 /ZnO(500A) under three substrate conditions, indicating the ZnO (0 0 2) peak reflects magneto crystalline anisotropy in the crystalline NiFe layer of ZnO(500A)/Ni 80 Fe 20 (YA), yielding the highest χ ac of approximately 3.16 with an f res of 250 Hz upon post-annealing T A  = 250 °C for 1 h. The (1 1 1) diffracted intensity and grain size of the thicker and post-annealed Ni 80 Fe 20 thin films exceeded those of the thinner and as-deposited Ni 80 Fe 20 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/Ni 80 Fe 20 (XA)/ZnO(500A) and as-deposited glass/ZnO(500A)/Ni 80 Fe 20 (YA) had the highest penetration, when X , Y  = 1000A, and the highest transmittances of 87% and 93%, respectively. The highest transmittance of glass/ZnO(500A)/Ni 80 Fe 20 (YA) exceeded that of glass/Ni 80 Fe 20 (XA)/ZnO(500A) owing to ZnO (0 0 2) crystallization. Furthermore, ρ decreased as the Ni 80 Fe 20 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/Ni 80 Fe 20 (1000A)/ZnO(500A) and glass/ZnO(500A)/Ni 80 Fe 20 (1000A) were 292 μΩ cm and 288 μΩ 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/Ni 80 Fe 20 (1000A)/ZnO(500A) and glass/ZnO(500A)/Ni 80 Fe 20 (1000A) had the highest surface energies of 64 mJ/mm 2 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/Ni 80 Fe 20 (XA)/ZnO(500A) was stronger than in glass/ZnO(500A)/Ni 80 Fe 20 (YA). The results indicate that the magnetic and photoelectric properties of glass/ZnO(500A)/Ni 80 Fe 20 (YA) were better than those of glass/Ni 80 Fe 20 (XA)/ZnO(500A) because the strong ZnO (0 0 2) crystallization in ZnO(500A)/Ni 80 Fe 20 (YA) increased the magneto crystalline anisotropy NiFe (1 1 1) and importantly affected the magnetic and photoelectrical properties.