Synthesis of Crystalline Skutterudite Superlattices Using the Modulated Elemental Reactant Method

Abstract

A series of samples ((AB)(x)(CD)(y))(z) were prepared containing both short repeat units (AB and CD) and long repeat units ((AB)(x)(CD)(y)), where the short repeat units were designed to have the composition appropriate to form square M(4)Sb(12) skutterudites (M = Fe, Co, or Ir; square = vacancy, La, or Y). X-ray diffraction and reflectivity were used to follow the evolution of the films from amorphous, layered materials to crystalline skutterudite superlattices as a function of annealing temperature and time. In all cases, the short repeat units interdiffused and crystallized the expected skutterudite, while the long repeat period persisted after annealing. The skutterudites crystallize with random crystallographic orientation with respect to the substrate. The observed splitting of the peaks in the high-angle diffraction data from the IrSb(3)/CoSb(3) sample indicates the formation of a novel superlattice structure with each grain having a random crystallographic orientation of the skutterudite lattice with respect to the superlattice direction.

Properties of thin N-type Yb0.14Co4Sb12 and P-type Ce0.09Fe0.67Co3.33Sb12 skutterudite layers prepared by laser ablation

“…7 There have been just a few different methods, for a thin skutterudite layer or a superattice deposition, published in literature up to date. These are magnetron rf sputtering, 6,8 simultaneous evaporation of elements which are components of skutterudite followed by temperature treatment in ambient or vacuum, [9][10][11][12] and pulsed laser deposition ͑PLD͒ from a skutterudite target. 5,7,9,13,14 In this contribution, we present the results obtained on thin P-type and N-type thermoelectric layers prepared at different deposition conditions by PLD method from Yb 0.19 Co 4 Sb 12 and Ce 0.1 Fe 0.7 Co 3.3 Sb 12 targets, respectively.…”

Understanding the Reactions Between Fe and Se Binary Diffusion Couples

“…Fe and Se were sequentially deposited to form compositionally modulated precursors in accordance with the modulated elemental reactants (MER) method. 21 Fe|Se bilayer, or repeat unit (RU), thicknesses were limited to less than 10 Å to minimize diffusion distances. Samples were removed from the deposition chamber and stored in a nitrogen glovebox (<0.2 ppm oxygen), where they were annealed or left as-deposited (AD).…”

The Deposition of Bi2Te3 and Sb2Te3 Thermoelectric Thin Films by Thermal Coevaporation and Applications in Energy Harvesting

“…As shown in the preceding section, the manipulation of the nanostructure in skutterudites has a significant influence on their TE properties, especially, nanostructures in bulk materials can markedly increase the concentration of the grain boundaries, and the lattice thermal conductivity may be reduced due to enhanced scattering effects on phonons [123,129,130,[133][134][135]. However, this scattering mechanism might have a similar effect on charge carriers too, so the electrical conductivity may be depressed to a certain degree.…”