Pressure induced phase transition in heavy fermion metal UTe2: A first-principles study

Heavy fermion metals are a strongly correlated electronic system with large effective mass of quasi-electrons. It also exhibits abundant physical properties at ambient pressure. Using crystal structure predictions and first-principles calculations, we found that an eight-fold coordinated ambient-pressure Immm phase of UTe2 transforms into a ten-fold coordinated high-pressure I4/mmm phase at 9 GPa. Considering the strong correlation effect of f electrons, the PBE + U method was used in our calculation. The ELF calculation results show that the pressure will facilitate the lone pair electrons of Te in ambient-pressure phase of UTe2 to participate in chemical bonding in order to achieve the high-pressure I4/mmm phase. Additionally, we found that the bulk modulus of the I4/mmm phase can reach 137 GPa. The work provides a possible route for studying phase transitions of UTe2 under pressure. (C) 2022 Published by Elsevier B.V.

Automated summary

The study investigates the phase transition of UTe2 under high pressure using crystal structure predictions and first-principles calculations. It reveals the transformation from an eight-fold coordinated ambient-pressure phase to a ten-fold coordinated high-pressure phase and explores the changes in physical properties associated with pressure.