The low-frequency alternative-current magnetic susceptibility and electrical properties of Si(100)/Fe40Pd40B20(X Å)/ZnO(500 Å) and Si(100)/ZnO(500 Å)/Fe40Pd40B20(Y Å) systems

Abstract

The two deposition conditions are (a) Si(100)/Fe40Pd40B20(X Å)/ZnO (500 Å) and (b) Si(100)/ZnO(500 Å)/Fe40Pd40B20(Y Å), where X and Y are 25 Å, 50 Å, 75 Å, and 100 Å. The sputtering sequence and the thickness of the FePdB film were varied to examine their effects on the low-frequency alternative-current magnetic susceptibility (χac), maximum phase angle (θmax), maximum χac with corresponding optimal resonance frequency (fres), and electrical resistivity (ρ). Experimental results show that ZnO(500 Å)/Fe40Pd40B20(Y Å) is superior to Fe40Pd40B20(X Å)/ZnO(500 Å) because the ZnO(002) texture at the bottom can improve the magneto nanocrystalline anisotropy of Fe40Pd40B20, improving its magnetic properties. In particular, a comparison of high-resolution cross-sectional transmission electron microscopy observations of Fe40Pd40B20(100 Å)/ZnO(500 Å) and ZnO(500 Å)/Fe40Pd40B20(100 Å) demonstrates that the ZnO(002) texture induces a magneto nanocrystalline anisotropy in the nanocrystalline FePdB layer of ZnO(500 Å)/Fe40Pd40B20(100 Å), yielding a highest χac of approximately 2.8 with an fres of 1000 Hz and an θmax of 169°. Additionally, the ρ is reduced as the FePdB thickness increases, because grain boundaries and the surface of thin films scatter the electrons, so thinner films have a greater resistance. The ρ of ZnO(500 Å)/Fe40Pd40B20(Y Å) is lower than that of Fe40Pd40B20(X Å)/ZnO(500 Å) because stronger ZnO crystallization and nanocrystalline FePdB improve the scattering of electrons by the surface of the films.