In the first part of this thesis, three intermetallic compounds are discussed, that were originally thought of as thallium iodide type compounds. Starting from small evidence that there is more than meets the eye, investigations began to find the true structure of AuIn. AuIn emerged to be modulated with various domain sizes over temperatures between room temperature and 400◦C, where at room temperature it shows satellite reflections up to third order that are fully replaced by diffuse scattering at 400◦C. While the atomic network is optically the
same at all temperatures, the space group changes from the incommensurate C-1(αβγ)0 at room temperature to Cmcm at 400◦C and the gold network appears as a Peierls type distorted version of the thallium network in TlI.
In addition the alloys PdBi and PdPb were examined with PdBi showing a very similar behaviour to AuIn, i.e. showcasing various degrees of modulation between room temperature and 300◦C and Pd adopting a Peierls type distorted version of the thallium network in TlI. For PdPb only room temperature data was measured so far, which also shows promising features of a Peierls type distorted thallium network for Pd.
The second part of the thesis addresses the alloy Sn3Sb2, which is a high temperature modification of stistaite, SnSb. Its structure can only be accessed in situ when a pre-grown crystal is mounted in a capillary with an additional
piece of tin. This sample has to be heated to a temperature of 250◦C to enable the structural transition. If the sample is monitored by X-ray diffraction during the heating process, the decay of the -tin reflections and the upsurge of the ordered Sn3Sb2 can be witnessed. Resulting is a structure consisting of 7x7x7 NaCl-type clusters interleaved by single Sn layers, presenting the space group Xm-3m.
These two parts are unified by both of them dealing with a simple structure type, which reveals modulation that can be studied in situ.
- Lidin, Sven, Supervisor
- Malm, Jan-Olle, Assistant supervisor
|Award date||2019 Dec 6|
|ISBN (electronic) ||978-91-7422-699-7|
|Publication status||Published - 2019|
Place: Lecture hall KC:B, Kemicentrum, Naturvetarvägen 14, Faculty of Engineering LTH, Lund University, Lund.
Name: Hadermann, Joke
Affiliation: Antwerp University, Belgium.
- Inorganic Chemistry
- Materials Chemistry