The Synthesis of Ce-Filled CoSb₃ and Characterization of its Magnetic and Structural Properties

Abstract

A series of cerium-containing CoSb3 samples were synthesized, with cerium quantities varying from 0 to 2 stoichiometric equivalents. These samples were annealed at low temperatures to crystallize the kinetically stable phases CexCo4Sb12 (x = 0–0.5). X-ray diffraction showed that these samples were phase pure, and Rietveld analysis on x-ray diffraction data from powder samples indicated that these samples were 25–88% crystalline. Electrical measurements showed that these samples are n-type, which was previously unknown in CexCo4Sb12. Magnetic measurements showed that the samples were paramagnetic due to the cerium being incorporated into the diamagnetic CoSb3 compound. In addition, they contained a ferromagnetic component that was attributed to the amorphous, cerium-containing phase.

Incomplete Crystallization of Skutterudites

“…The series of Ce x Co 4 Sb 12 samples was synthesized with x = 0 to 2, based on EPMA analysis, and analyzed fully elsewhere [2]. The sample compositions were normalized to full filling of the metal site.…”

“…The samples were X-ray amorphous as deposited, but crystallized when heated to moderate temperatures (200 -300 °C), and showed only the skutterudite phase in the X-ray diffraction scans. 2 increased as more cerium was included in the sample (see Table I). We observed several trends in the data: first, that the lattice size increased with increasing amount of cerium content (see Table II).…”

“…Samples were annealed for one hour at a time in a Thermolyne 1500 box furnace under nitrogen atmosphere, at temperatures sufficient to crystallize the samples (detailed elsewhere) [2]. Samples were annealed for one hour at a time in a Thermolyne 1500 box furnace under nitrogen atmosphere, at temperatures sufficient to crystallize the samples (detailed elsewhere) [2].…”

“…For example, in a series of cerium-filled CoSb 3 samples it was necessary to add excess cerium to the samples in order to achieve more complete filling of the void sites [1,2]. For example, in a series of cerium-filled CoSb 3 samples it was necessary to add excess cerium to the samples in order to achieve more complete filling of the void sites [1,2].…”

Ce Filling Limit and Its Influence on Thermoelectric Performance of Fe3CoSb12-Based Skutterudite Grown by a Temperature Gradient Zone Melting Method

“…Besides, the thin film CoSb 3 sample prepared by deposition experienced increased Ce-filling fraction. Smalley et al [41] reported a high Ce-filling fraction of ~0.55 in deposited CoSb 3 film.…”