Role of magnetization parameters in designing high-performance spin-driven thermoelectrics

Magnetic short-range order above the ordering temperature in some magnetic semiconductors,

usually layered materials, can lead to a high thermopower extending to elevated temperatures

deep in the paramagnetic domain. In this regard, the magnitude and temperature dependence

of the short-range order are critical parameters for designing high-performance spin-driven

thermoelectrics, which we discuss in this presentation. Due to the type of the magnetic and

lattice structures and the interactions between the magnetic ions, the short-range order can vary

in amplitude and temperature extension in different lattice directions. Furthermore, such

interactions affect the magnitude of the ordering temperature, which allows the designing of

thermoelectric materials for a target working temperature. We will discuss the material

parameters involved in magnetic semiconductors with sizable short-range order parameters

extending well above the order transition temperature. The results are vital in designing

paramagnetic thermoelectrics with large thermopowers, which has taken increasing attention

recently.