Siam Physics Congress 2015

May 20 – 22, 2015
Asia/Bangkok timezone
The Centennial Celebration of General Relativity Theory and 80 Years of Thai Physics Graduate

$Ab$ $initio$ calculations of structural phase transitions of XP compounds (X=La, Ce, Pr, and Nd) under high pressure

May 20, 2015, 2:30 PM
15m
Hemingways' Lounge

Hemingways' Lounge

Oral presentation Condensed Matter Physics

Speaker

Mr Chirayu Sainamthip (Mahidol Wittayanusorn School, Nakhon Pathom 73170, Thailand)

Description

Lanthanide-monophosphate materials have been used in many applications, such as scintillators for detecting radiation and inorganic fluorescent labels. In this work, high-pressure phase transitions of XP (X = La, Ce, Pr, and Nd) have been undertaken. Based on density functional theory (DFT), the energetic stability of XP materials were investigated to verify the most stable structures at pressure ranges. NaCl-type, CsCl-type, PbO-type, and P4/mmm which are based on related experimental results, were chosen to carry out in all XP materials. Using local density approximation (LDA), the results reveal that all compounds exhibit the NaCl-type structure at ambient pressure which is in good agreement with the experiments. LaP, CeP and NdP transform by the path of NaCl-type → PbO-type → CsCl-type structure. Moreover, CeP continuously undergoes the transformation to P4/mmm structure. In contrast, PrP passes P4/mmm phase before approaching PbO-type structure. Electronic density of states (DOS) and band structures were performed to clarify the phenomenon of high-pressure phase transitions of these compounds.

Primary author

Mr Chirayu Sainamthip (Mahidol Wittayanusorn School, Nakhon Pathom 73170, Thailand)

Co-authors

Mr Komsilp Kotmool (Department of Physics, Mahidol Wittayanusorn School, Nakhon Pathom 73170 Thailand; Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand) Mr Pornmongkol Jimlim (Department of Physics, Mahidol Wittayanusorn School, Nakhon Pathom 73170, Thailand) Thiti Bovornratanaraks (Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand)

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