Abstract
Angle-dispersive x-ray powder diffraction experiments have been performed on praseodymium metal to a pressure of 205 GPa. Between 20 and 165 GPa only the
oC4 (α-uranium) phase is observed, in agreement with previous studies. At 171(5) GPa we find a transition to a tetragonal tI2 phase which is isostructural with the high-pressure post-oC4 phase seen in the neighboring lanthanide cerium above 12 GPa, and with the high-pressure phase of the actinide thorium seen above 100 GPa. Electronic structure calculations determine the oC4→tI2
transition to occur at 130 GPa at 0 K, but find another phase, with the hP1
(simple hexagonal) structure, to have a lower enthalpy than both the oC4
and tI2 structures above 20 GPa at 0 K.
oC4 (α-uranium) phase is observed, in agreement with previous studies. At 171(5) GPa we find a transition to a tetragonal tI2 phase which is isostructural with the high-pressure post-oC4 phase seen in the neighboring lanthanide cerium above 12 GPa, and with the high-pressure phase of the actinide thorium seen above 100 GPa. Electronic structure calculations determine the oC4→tI2
transition to occur at 130 GPa at 0 K, but find another phase, with the hP1
(simple hexagonal) structure, to have a lower enthalpy than both the oC4
and tI2 structures above 20 GPa at 0 K.
Original language | English |
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Article number | 174104 |
Pages (from-to) | 1-8 |
Number of pages | 8 |
Journal | Physical Review B |
Volume | 105 |
Issue number | 17 |
DOIs | |
Publication status | Published - 9 May 2022 |