Search: id:"swepub:oai:DiVA.org:kth-223668" > Finite temperature ...
Fältnamn | Indikatorer | Metadata |
---|---|---|
000 | 04736nam a2200373 4500 | |
001 | oai:DiVA.org:kth-223668 | |
003 | SwePub | |
008 | 180227s2018 | |||||||||||000 ||eng| | |
020 | a 9789177296874q print | |
024 | 7 | a https://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-2236682 URI |
040 | a (SwePub)kth | |
041 | a engb eng | |
042 | 9 SwePub | |
072 | 7 | a vet2 swepub-contenttype |
072 | 7 | a dok2 swepub-publicationtype |
100 | 1 | a Ehteshami, Hosseinu KTH,Materialvetenskap4 aut0 (Swepub:kth)u11ohzu9 |
245 | 1 0 | a Finite temperature properties of elements and alloy phases from first principles |
264 | 1 | a Stockholm :b KTH Royal Institute of Technology,c 2018 |
300 | a 78 s. | |
338 | a electronic2 rdacarrier | |
500 | a QC 20180228 | |
520 | a First principles calculations are usually concerned with properties calculated at temperature 0 K. However, the industrially important materials are functioning at finite temperatures. To fill such a gap a first-principles based modeling of free energy has been developed in this thesis and finite temperature properties of different phases of Fe and Mn have been calculated and contrasted with available experimental data.In particular, using partitioning of the Helmholtz free energy, thermophysical properties of paramagnetic Fe have been reported. The heat capacity, lattice constant, thermal expansion and elastic moduli of γ- and δ-Fe show a good agreement with available experimental data. In the case of α-Fe, we observe a good agreement for elastic moduli and thermal expansion with experiments but the heat capacity is not well-reproduced in the calculations because of the large contribution of magnetic short-range which our models are not capable of capturing.α- and β-Mn theoretically pose a challenge for direct simulations of thermodynamic properties because of the complexity of magnetic and crystal structure. The partitioning of free energy has been used and thermodynamics of these phases have been derived. The obtained results show a good agreement with experimental data suggesting that, despite the complexities of these phases, a rather simple approach can well describe their finite temperature properties. High temperature phases of Mn, γ and δ, are also theoretically challenging problems. Employing a similar approach to Fe, thermophysical properties of these high symmetry phases of Mn have been reported which also show good agreement with available experimental data.The point defect and metal-self diffusion in titanium carbide (TiC), a refractory material, have been investigated in the present work. The common picture of metal-vacancy exchange mechanism for metal self-diffusion was shown to be unable to explain the experimentally observed values of activation energy. Several new clusters of point defects such as vacancies and interstitials have been found and reported which are energetically lower that a single metal vacancy. In a subsequent study, we showed that some of these clusters can be considered as mediators of metal self-diffusion in TiC.Evaluation of structural properties of Ti(O,C), a solid solution of TiC and β-TiO, from supercell approach is an extremely difficult task. For a dilute concentration of O, we show the complexity of describing an impurity of O in TiC using supercell approach. A single-site method such as the exact muffin-tin orbital method in the coherent potential approximation (EMTO-CPA) is a good alternative to supercell modeling of Ti(O,C). However, a study of Ti(O,C) using EMTO-CPA requires a further development of the technique regarding the partitioning of space. The shape module of EMTO has been modified for this purpose. With the help of the modified module, Ti(O,C) have been studied using EMTO-CPA. The results for the divacancy concentration and corresponding lattice parameter variations show good agreement with experimental data. | |
650 | 7 | a NATURVETENSKAPx Fysikx Den kondenserade materiens fysik0 (SwePub)103042 hsv//swe |
650 | 7 | a NATURAL SCIENCESx Physical Sciencesx Condensed Matter Physics0 (SwePub)103042 hsv//eng |
653 | a Materials Science and Engineering | |
653 | a Teknisk materialvetenskap | |
653 | a Physics | |
653 | a Fysik | |
700 | 1 | a Korzhavyi, Pavel A.,d 1966-u KTH,Materialvetenskap4 ths0 (Swepub:kth)u17nfa0i |
700 | 1 | a Ruban, Andrei V.u KTH,Materialvetenskap4 ths0 (Swepub:kth)u1uo08he |
700 | 1 | a Hickel, Tilmann,c Dr.u Max-Planck-Institut für Eisenforschung GmbH4 opn |
710 | 2 | a KTHb Materialvetenskap4 org |
856 | 4 | u https://kth.diva-portal.org/smash/get/diva2:1186245/FULLTEXT01.pdfx primaryx Raw objecty fulltext |
856 | 4 8 | u https://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-223668 |
Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.