This dissertation is dedicated to investigating the thermoelectric properties of the
Zn – Sb phases and particularly the Zn13Sb10 material, which was shown to achieve a high
ZT (1.3 at 670K) in 1997. The Zn13Sb10 material (known as “Zn4Sb3”) was then
extensively studied as a potential thermoelectric material. The Zn13Sb10 materials,
however, were not widely adapted in thermoelectric applications.
A new synthetic procedure was developed to synthesize phase-pure Zn13Sb10
materials in this thesis, thus allowing a robust characterization of the Zn13Sb10-based
materials. This work aims to improve the thermoelectric performance of the Zn13Sb10-
based materials by substituting foreign elements into the structure of the Zn13Sb10 phase,
at the same time characterize and navigate the synthesis-property-composition
relationship of the doped Zn13Sb10 materials.
On the other hand, some relative Zn–Sb phases such as the α- and β-Zn3Sb2 were
also studied in attempt to complete the characterizations of all Zn–Sb phases stable at
room temperatures. The ZnSb phase, another well-studied Zn–Sb material, was
investigated in coherence with the Zn13Sb10 materials to understand the effects to
transport properties brought by the same atom replacement in the two systems. This was
realized in the form of a comparison between the (Zn,Cd)Sb and (Zn,Cd)13Sb10 solid
solution series.
Materials studied in this work were mostly made using the melt and solidification
method. Powder and single-crystal X-ray diffractions were employed to characterize
samples’ purity and structure determination. Energy-dispersive X-ray Spectroscopy (EDS)
was used to determine sample compositions, especially to confirm the presence(s) of
dopants in materials in small quantities. Physical properties of materials were measured to
evaluate the thermoelectric performances of materials. Computational methods, such as
the linear muffin-tin orbital (LMTO) method was used to help understand the transport
properties of materials and the electron localization function (ELF) method to analyze the
bonding natures between atoms. / Thesis / Doctor of Philosophy (PhD) / Thermoelectric materials are incorporated into thermoelectric devices to generate
electricity from heat sources. As there are environmental concerns and increasing demand
of energy supplies in the society, thermoelectricity may relieve some of the pressure by
waste heat recovery, from internal combustion engines for example.
This work is dedicated to studying the zinc–antimony (Zn–Sb) materials and a
focus on the Zn13Sb10 material for thermoelectric applications. This work aims to improve
the thermoelectric efficiency of the Zn13Sb10 material, at the same time understand the
changes on the physical properties brought by the structural and the compositional
differences of the material. The relative Zn–Sb phases, such as ZnSb and Zn3Sb2, were
also characterized to compare their structures with their physical properties.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/27815 |
| Date | January 2022 |
| Creators | Lo, Chun-wan Timothy |
| Contributors | Mozharivskyj, Yurij, Chemistry |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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