Magnetic semiconducting chalcogenide spinels: Preparation and physical chemistry

Systematic crystal-chemical studies of chalcogenide spinels and related phases are used to develop a novel, unified approach to analyzing the nonstoichiometry of close-packed phases in the series atacamite–spinel–halite with allowance for alternatively occupied tetrahedral and octahedral nonatacamite sites. The main physicochemical approaches to the synthesis and crystal growth of magnetic semiconducting chalcogenide spinels are considered. The phase diagrams of systems containing magnetic semiconducting phases are mapped out. To choose flux growth conditions, the liquidus relations in spinel–solvent systems and the kinetics of mass transport in chemical vapor transport systems are investigated. The influence of high temperatures and pressures on the structure of polycrystalline chalcogenide spinels is analyzed. The purity of the starting materials is shown to have a significant effect on the physical properties of chalcogenide spinels. Physical property measurements demonstrate that the magnetic semiconducting chalcogenide spinels have considerable potential for practical application.