Synthesis and electrical conductivity of nanocrystalline tetragonal FeS
Zeng Shu-Lin (曾树林)a b, Wang Hui-Xian (王辉宪)a, Dong Cheng (董成)b
a Hunan Agricultural University, Changsha 410128, China;
b Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
Abstract A convenient method for synthesis of tetragonal FeS using iron powder as iron source, is reported. Nanocrystalline tetragonal FeS samples were successfully synthesized by reacting metallic iron powder with sodium sulfide in acetate buffer solution. The obtained sample is single-phase tetragonal FeS with lattice parameters a = 0.3767 nm and c =0.5037 nm, as revealed by X-ray diffraction. The sample consists of flat nanosheets with lateral dimensions from 20 nm up to 200 nm and average thickness of about 20 nm. We found that tetragonal FeS is a fairly good conductor from the electrical resistivity measurement on a pellet of the nanosheets. The temperature dependence of conductivity of the pellet was well fitted using an empirical equation wherein the effect of different grain boundaries was taken into consideration. This study provides a convenient, economic way to synthesize tetragonal FeS in a large scale and reports the first electrical conductivity data for tetragonal FeS down to liquid helium temperature.
Fund: Project supported by the National Natural Science Foundation of China (Grant No. 21271183) and the National Basic Research Program of China (Grant Nos. 2011CBA00112 and 2011CB808202).
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