Materials discovery using in situ reduction and X-ray diffraction

Materials discovery is important for pushing new and existing technologies forward. In this thesis, a systematic approach to materials discovery is presented that highlights the combined use of in situ reduction reactions and X-ray diffraction to quickly explore compositional space. Reduction reactions provide a synthesis route that has been shown to gently traverse a compositional space. Traditional synthesis at high temperatures tends to only favor the formation of thermodynamically stable compounds, however, with a more controlled synthesis route, kinetically stable and metastable compounds may be easier to discover. By coupling reduction reactions with in situ X-ray diffraction, intermediate and metastable phases can be observed. Once a phase is observed using in situ X-ray diffraction, attempts can be made to stabilize the phase ex situ in order to solve the structure and understand the material's properties. In this thesis, an in situ cell is described that can be used to perform these in situ reduction reactions using a laboratory X-ray diffractometer. Since the technique can now be performed on a laboratory scale, rapid phase exploration can be performed. This combined approach will be discussed with regard to two different materials systems, K-Sn-O and Fe-S. In the K-Sn-O system, in situ and ex situ studies are performed in order to search for new p-type transparent conducting oxides. In the Fe-S system, in situ reduction is used to solve a highly debated question of whether or not pyrite FeS2 is a non-stoichiometric compound and to quantify the possible extent of non-stoichiometry.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Materials Science & Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2019

Author dc:creator

• McAuliffe, Rebecca D.

Contributors dc:contributor

• Shoemaker, Daniel P.
• Zuo, Jian-Min
• Perry, Nicola H.
• Cooper, Lance

• materials discovery, in situ X-ray diffraction, reduction reactions

Statement dc:rights

• Copyright 2018 Rebecca D. McAuliffe

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/102910

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/102910