Fabrication and Magnetic Properties of Fe₆₅Co₃₅–ZnO Nano-Granular Films

• Main Authors: Wang Guowei, Zhang Feng, Zuo Huaping, Yu Zhenhua, Ge Shihui
• Format: Article
• Language: English
• Published: SpringerOpen 2010-01-01
• Series: Nanoscale Research Letters
• Subjects: Nano-granular film; Soft magnetic material; High frequency property; Exchange coupling
• Online Access: http://dx.doi.org/10.1007/s11671-010-9609-y

<p>Abstract</p> <p>A series of nano-granular films composed of magnetic metal (Fe₆₅Co₃₅) granules with a few nanometers in size and semiconductor oxide (ZnO) have been fabricated by a magnetron sputtering method, and excellent soft magnetic properties have been achieved in a wide metal volume fraction (<it>x</it>) range for as-deposited samples due to the exchange coupling between FeCo granules (a ferromagnetic interaction in nano-scale). In a wide range (0.53 &lt; <it>x</it> &lt; 0.71), the films exhibit coercivity <it>H</it> _<it>C</it> not exceeding 15 Oe, along with high resistivity. Especially for the sample with <it>x</it> = 0.67, coercivities in hard and easy axes are 1.43 and 7.08 Oe, respectively, 4&#960;<it>M</it> _<it>S</it> = 9.85 kg, and <it>&#961;</it> reaches 2.06 &#215; 10³ &#956;&#937; cm. The dependence of complex permeability <it>&#956;</it> = <it>&#956;</it>&#8242; &#8722; <it>j&#956;</it>&#8243; on frequency shows that the real part <it>&#956;&#8242;</it> is more than 100 below 1.83 GHz and that the ferromagnetic resonance frequency reaches 2.31 GHz, implying the promising for high frequency application. The measured negative temperature coefficient of resistivity reveals that may be the weak localized electrons existing in samples mediate the exchange coupling.</p>