铁硫化物球粒

IRON SULPHIDE SPHERULES

铁硫化物的合成，通常是通过固-气反应来实现，本文利用电弧放电的方法．使黄铁矿（FeS2）还原成磁黄铁矿（Fe1－xS）、陨硫铁（FeS）和金属铁（Fe）。利用反光显微镜（RLM）、X射线衍射（XRD）、扫描电镜（SEM）、透射电镜（TEM）和能谱（EDS）技术综合研究合成物的特征及各物相的相互关系。初步研究了合成物的电学和磁学性能。讨论在电弧作用的还原环境里，FeS2向FeS、Fe1-xS和Fe转变的特征。

In the laboratory. iron sulphides were synthesized mainly by way of gas-solid reaction ofmetallic iron or iron-nickel alloys with the mixture of H,S and H,. The arc-discharge method wasemployed to synthesize iron sulphides in this study. The anode was composed of pyrite andgraphite, and thee cathode was a pure graphite mass. The synthetic experiments were performed ina He-filled arc-charge evaporation chamber. The He pressure was (6. 0 - 7. 0) × 104Pa. the discharge voltage 28- 32V. the current 65-70A and the distance between the two electrodes 2mm.The synthetic spherules are up to 2-3mm in diameter and composed of about 85% troilite, 12%pyrrhotite and 3% metallic iron. There are nano-sized hollow carbon filaments and carbon balls onthe surface of the spherules. In this study the features and coexisting relationships of these constituents of the spherules were studied by RLM, XRD, EDS, SEM and TEM, and the transformation was examined of pyrite (FeS, ) into pyrrhotite (Fe1-x S ). troilite (FeS) and metallic iron(Fe ) under arc-discharge reducing conditions. Results indicated that the spherules have the electrical features of semiconductivity and the features of soft magnetic materials.