Experimentelle Untersuchungen zu Mechanismen von druck- und temperaturinduzierten Phasenübergängen

Experimental examinations of mechanisms of pressure- and temperature-induced phase transitions

by Nina Katrin Pukallus
Doctoral thesis
Date of Examination:2020-10-22
Date of issue:2021-10-18
Advisor:Dr. Heidrun Sowa
Referee:Dr. Heidrun Sowa
Referee:Dr. Helmut Klein
Referee:Prof. Dr. Sharon Webb
Persistent Address: http://dx.doi.org/10.53846/goediss-8885

 

 

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Abstract

English

Under the influence of pressure and/or temperature changes, crystalline materials undergo a phase transition. The directions of the crystalline unit cell before and after the phase transition can show orientation relations. These orientation relations can give clues about the atomar transition mechanism, which is expressed in group-subgroup relations via a common subgroup of both end configurations. The behaviour of crystalline materials during their phase transition was experimentally studied using synchrotron radiation and a diamond anvil cell respectively a graphite band-heated oven. The following five materials were used: indium arsenide, cadmium sulfide, cadmium selenide, copper indium diselenide and nickel sulfide. For the pressure-induced phase transition of indium arsenide no transformation path with a common subgroup could be found, but the orientation relations between high-pressure and low-pressure phase could be determined and the atomar mechanism of the transition could be derived. The orientation relations between the high-pressure and low-pressure phase of copper indium diselenide pointed to multiple possible transition paths. For the pressure-induced phase transition of cadmium sulfide and cadmium selenide, already assumed orientation relations and their correlating transition path could be confirmed. For the temperature-induced phase transition of nickel sulfide also an already assumed transition path could be confirmed, but no transition path via a common subgroup.
Keywords: crystallography; phase transitions; orientation relations; semiconductors; indium arsenide; copper indium diselenide; cadmium sulfide; cadmium selenide; nickel sulfide; synchrotron radiation; diamond-anvil cell
Schlagwörter: Kristallographie; Phasenübergang; Orientierungsbeziehungen; Halbleiter; Indiumarsenid; Kupfer-Indium-Diselenid; Kadmiumsulfid; Kadmiumselenid; Nickelsulfid; Synchrotronstrahlung; Diamantstempelzelle
 
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