کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1596952 | 1002872 | 2007 | 6 صفحه PDF | دانلود رایگان |
A systematic investigation of Eu-doped Nd-based colossal magnetoresistive manganites with compositional formula Nd0.67−yEuySr0.33MnO3(y =0–0.67) has been undertaken to understand their structural, magnetic as well as electrical behavior. These materials were prepared by the citrate gel route, and were later characterized by X-ray diffraction (XRD), AC susceptibility, electrical resistivity etc; measurements. A detailed structural characterization of the XRD data has also been undertaken, using Rietveld refinement method. From a systematic analysis of electrical resistivity versus temperature data, it has been found that the last two samples of the series (y=0.57y=0.57 and 0.67) are found to exhibit charge order (CO) phenomenona, and that the CO state melts completely in the case of former sample (y=0.57)(y=0.57) while it melts partially only in the case of later one (y=0.67)(y=0.67), even in a magnetic field of 7 T. The observed behavior has been explained qualitatively. Some of the samples of the series are found to exhibit unusually large magnetoresistance over a wide temperature range in the low temperature region, and their behavior has been explained on the basis of phase segregation and an inter-grain spin polarized tunneling effect.
Journal: Solid State Communications - Volume 141, Issue 2, January 2007, Pages 73–78