Observation of lattice defects in orthorhombic iron disulfide (marcasite)

Different types of lattice defects have been studied by transmission electron microscopy (TEM) at 100 and 200 kV in a sample of natural marcasite. The most frequently occurring Burgers vectors are b=[001], [100] and 〈101〉. Dislocations with large Burgers vectors (b=〈110〉 and 〈111〉) have also been characterized: these are possibly split. Interactions between the different dislocations result in a build-up of dislocation networks. Dislocation structures show that the sample has undergone a strong recovery. These observations are confirmed by metallographic and scanning electron microscopy (SEM) observations after chemical etching.