ABSTRACT
Energy production from clean, renewable, and sustainable sources with efcient energy conversion is necessary to tackle the fast continuing growth of the global demand for energy. For instance, there is an increasing demand for low-power consumption, high-performance miniaturized devices such as cellular phones, digital cameras, and MP3 players, which is driving research activities to develop nonvolatile memory devices and ultrahighdensity information storage spin-based devices for computing [1,2] and spintronic [3] applications. In addition, substantial increases in research activities in the areas of photovoltaic and thermoelectric energy production technologies over the past six decades have led to signicant improvements in materials performance. However, the development of thermoelectric materials with the gure of merit ZT ≥ 3 (ZT = TσS2/κ, where σ is the electrical conductivity; S is the Seebeck coefcient, often called the thermopower; and κ is the thermal conductivity) necessary for the realization of cost-effective solid-state energy conversion devices capable of competing with traditional mechanical energy conversion systems has proven extremely difcult, mainly because of the interdependence and coupling between electronic and thermal parameters. In conventional semiconductors, the electrical conductivity (σ) and thermopower (S) are fundamentally adversely coupled through the concentration of charge carriers, n. For instance, in most good thermoelectric materials,
CONTENTS
7.1 Introduction ........................................................................................................................ 237 7.2 Half-Heusler Alloys as Promising Thermoelectric Materials .....................................238 7.3 Bulk Nanostructured Half-Heusler Composites ........................................................... 240
7.3.1 Synthesis, Processing, and Microstructure ........................................................ 240 7.3.2 Electronic Transport in Half-Heusler Nanocomposites with
Full-Heusler and InSb Inclusions ........................................................................ 247 7.3.2.1 HH Matrix with Large FH Inclusions .................................................. 247 7.3.2.2 HH Matrix with Small FH Inclusions ..................................................253 7.3.2.3 HH Matrix with InSb Nanoinclusions .................................................280
