Electrical and Magnetic Properties of Sulfides

Abstract

The metal sulfides exhibit a great diversity of electrical and magnetic properties with both scientific interest and practical applications. These properties apply major constraints on models of the electronic structure (or chemical bonding) in sulfides (Vaughan and Rosso 2006, this volume). The pure and doped synthetic equivalents of certain sulfide minerals have actual or potential applications in the electronics industries (optical devices, photovoltaics, photodiodes and magnetic recording devices). Sulfides are also components of many thin film devices and have been extensively investigated as part of the nanotechnology revolution. Certain electrical and magnetic properties of sulfide minerals mean they contribute to geomagnetism and paleo-magnetism, and provide the geophysical prospector with exploration tools for metalliferous ore deposits. To the mineral technologist, these same properties provide methods for the separation of the metal-bearing sulfides from associated waste minerals after mining and milling and before extraction of the metal by pyrometallurgical or hydrometallurgical treatment. In this chapter, the theory and measurement of electrical and magnetic properties are outlined along with spectroscopic and diffraction studies that can provide insights into magnetic behavior are discussed. A brief review of electrical and magnetic studies of major sulfide minerals includes some examples of the applications of sulfide electrical and magnetic properties, including special consideration of the properties of sulfide nanoparticles. Most of the available data presented are for pure synthetic binary and ternary sulfides, as very small concentrations of impurities can dramatically affect electrical properties leading to problems of interpreting data from natural samples. Although data for several of the commonly found sulfides are discussed in this chapter, no attempt is made at a comprehensive coverage. The section below on theory and measurement of electrical and magnetic properties draws on the account given in Vaughan and Craig (1978) to which readers are referred for further details. It …