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In this article, DyxFe100-x nanogranular (15 ≤ x ≤ 25) thin films have been prepared at ambient temperature by dc magnetron sputtering. The correlation between the microstructure, magneto transport and magnetization properties is discussed. The grain size of Dy (Dysprosium) and Fe (Iron) was measured to be about 2 to 3nm, respectively and the distribution of grains was homogenous throughout the sample. The magnetoresistance is sensitive to microstructural changes (particle size as well as Dy concentration). At the room temperature, the magnetoresistance [MR %] increased from 0.2 to 2.2 with increase in atomic concentration of Dy from x = 15 to 25 and we obtained maximum 2.2 MR [%] for x = 25 in this series of samples. The magnetization studies have revealed that all the samples are superparamagnetic (SPM) at room temperature. [ABSTRACT FROM AUTHOR]

In the present study, the structural and magnetic properties of the Fe70Dy30 thin films are investigated. The Fe70Dy30 thin film with a thickness of 250 Å is fabricated using a dc magnetron sputtering system. Structural and temperature dependent magnetic properties indicate the granular nature of the film. The nonsaturation of the magnetization curves even at high fields of 50 kOe and the obtained very low coercivity in the temperature range 50 – 300 K reveal that films are superparamagnetic (SPM). The decreasing blocking temperature (Tb) with increasing an external magnetic field in temperature dependent magnetization curves are exposed qualitatively. [ABSTRACT FROM AUTHOR]