TY - JOUR
T1 - Comparing the compression behavior of the antiperovskites CePt3Si, CePt3B, and YPt3B from combined X-ray diffraction experiments and density functional theory
AU - Ehrenreich-Petersen, Emma
AU - Nielsen, Morten B.
AU - Ceresoli, Davide
AU - Ottesen, Martin
AU - Parisiades, Paraskevas
AU - Bremholm, Martin
PY - 2025/1/5
Y1 - 2025/1/5
N2 - In this study we report the synthesis three antiperovskites YPt3B, CePt3B, and CePt3Si as well a focused investigation of YPt3B, which all have the same P4mm symmetry with a large c∕a ratio at ambient conditions. The compounds are investigated under high-pressure using powder X-ray diffraction in diamond anvil cells. A structural transition is found to occur in the YPt3B compound at 23(2) GPa caused by the softening of a zone boundary phonon. Using a combination of symmetry analysis and structural prediction, the high-pressure phase is assigned to a structure described by the P2 (P121) space group. Calculation of the phonon dispersion confirms that this structure is dynamically stable with A = Ce, Y and Z = Si, B. It was found that the three APt3Z compounds behave differently with pressure. The bulk moduli for the three compounds are found to be 185(5) GPa, 155(3) GPa, and 128(2) GPa for YPt3B, CePt3B, and CePt3Si, respectively. We found that the Z atom moves away from the center with pressure for A = Ce along the c-axis, whereas for A = Y, the Z atom stays in the approximately same position. This behavior is also reflected in their c∕a ratio which stays approximately constant in YPt3B. Overall we find that the Ce-bearing compounds are more compressible in the ab-plane, reducing the tilting of the octahedra. As a result, in YPt3B and CePt3B the transition to the structure described by the P2 space group is likely to occur at higher pressures.
AB - In this study we report the synthesis three antiperovskites YPt3B, CePt3B, and CePt3Si as well a focused investigation of YPt3B, which all have the same P4mm symmetry with a large c∕a ratio at ambient conditions. The compounds are investigated under high-pressure using powder X-ray diffraction in diamond anvil cells. A structural transition is found to occur in the YPt3B compound at 23(2) GPa caused by the softening of a zone boundary phonon. Using a combination of symmetry analysis and structural prediction, the high-pressure phase is assigned to a structure described by the P2 (P121) space group. Calculation of the phonon dispersion confirms that this structure is dynamically stable with A = Ce, Y and Z = Si, B. It was found that the three APt3Z compounds behave differently with pressure. The bulk moduli for the three compounds are found to be 185(5) GPa, 155(3) GPa, and 128(2) GPa for YPt3B, CePt3B, and CePt3Si, respectively. We found that the Z atom moves away from the center with pressure for A = Ce along the c-axis, whereas for A = Y, the Z atom stays in the approximately same position. This behavior is also reflected in their c∕a ratio which stays approximately constant in YPt3B. Overall we find that the Ce-bearing compounds are more compressible in the ab-plane, reducing the tilting of the octahedra. As a result, in YPt3B and CePt3B the transition to the structure described by the P2 space group is likely to occur at higher pressures.
KW - Crystal structure prediction
KW - Equation of state
KW - High pressure
KW - Phonons
KW - Symmetry
KW - X-Ray diffraction
UR - https://www.scopus.com/pages/publications/85207690407
U2 - 10.1016/j.jallcom.2024.177204
DO - 10.1016/j.jallcom.2024.177204
M3 - Journal article
AN - SCOPUS:85207690407
SN - 0925-8388
VL - 1010
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
M1 - 177204
ER -