Thermoelectric and Magnetic Properties of Snclass="a-plus-plus">1−class="a-plus-plus">x Oclass="a-plus-plus">2:Mnclass="a-plus-plus">0.5class="a-plus-plus">x Coclass="a-plus-plus">0.5class="a-plus-plus">x Nanoparticles Produced by the Microwave Technique
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- 作者：Numan Salah ; Sami Habib ; Ameer Azam
- 关键词：Mn ; Co co ; doped SnO2 nanoparticles ; thermoelectric properties ; magnetic properties ; microwave
- 刊名：Journal of Electronic Materials
- 出版年：2017
- 出版时间：February 2017
- 年：2017
- 卷：46
- 期：2
- 页码：1190-1200
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Optical and Electronic Materials; Characterization and Evaluation of Materials; Electronics and Microelectronics, Instrumentation; Solid State Physics;
- 出版者：Springer US
- ISSN：1543-186X
- 卷排序：46
文摘
Nanoparticles (NPs) of Sn1−class="EmphasisTypeItalic ">xO2:Mn0.5xCo0.5x with x = 0.02, 0.04, 0.06, 0.08 and 0.1 were synthesized by the microwave-assisted route and characterized for their thermoelectric and magnetic properties. As a result of Mn and Co co-doping, a considerable increase in the values of energy band gap and lattice constant c of Sn1−class="EmphasisTypeItalic ">xO2:Mn0.5xCo0.5x NPs was observed. The x-ray photoelectron spectroscopy spectra revealed that Mn and Co ions were incorporated in their 4+ and 2+ states, respectively. The resistivity and calculated activation energy of these NPs were found to decrease by increasing the Mn and Co contents. A negative Seebeck coefficient was observed, whose value was found to be significantly increased by increasing the value of x. The magnetic measurement results revealed that all the microwave-synthesized Sn1−class="EmphasisTypeItalic ">xO2:Mn0.5xCo0.5x NPs including the pure SnO2 have distinctly wide hysteresis loops. This indicates that samples have room-temperature ferromagnetism. The optimum value for x to have maximum saturation magnetism was observed to be 0.04. Diamagnetic contributions from the core of these NPs were noticed at higher magnetic fields. The observed magnetism was attributed to the presence of defects at the NPs' interfacing sites, grain boundaries, atom vacancies and an optimum level of Mn and Co co-dopants. The observed wide hysteresis loops in these NPs might be useful for producing nanoscale magnets and magnetic memory devices. Moreover, the observed thermoelectric properties, i.e. Seebeck coefficient and power factor in these NPs, might be useful for the development of thermoelectric devices.