The crystal structure and magnetic properties of YCo5 compound have been studied by neutron diffraction,in the pressure range 0≤p≤7.2 GPa.The cobalt moments decrease with pressure,parallelly with anisotropic changes...The crystal structure and magnetic properties of YCo5 compound have been studied by neutron diffraction,in the pressure range 0≤p≤7.2 GPa.The cobalt moments decrease with pressure,parallelly with anisotropic changes of lattice parameters.The experimental data are analyzed together with results from the combined Density Functional and Dynamical Mean-Field Theory.A rather good agreement between the experimentally determined and calculated values of cobalt moments is shown.Our scenario for the behavior of YCo5 under pressure,is the combined action of the Lifshitz transition with a strong local electron-electron interaction.展开更多
The evolution of the structural and electronic properties of the van der Waals layered ferromagnet CrBrs across the semiconductor-metal transition was investigated using X-ray powder diffraction and Raman spectroscopy...The evolution of the structural and electronic properties of the van der Waals layered ferromagnet CrBrs across the semiconductor-metal transition was investigated using X-ray powder diffraction and Raman spectroscopy at high pressures up to 38 GPa and by density functional theory(DFT)calculations at high pressures up to 120 GPa.The pressure behavior of the structural parameters and vibrational modes revealed a crossover from the quasi-two-dimensional system with weakly interacting atomic layers to the three-dimensional-like system with strongly interacting layers at P~15 GPa.This resulted in a significant modification of the pressure coefficients of the lattice parameters and interlayer distances.DFT calculations using first-principles generalized gradient ap-proximations of the Perdew-Burke-Ernzerhof(PBE)and Perdew-Burke-Ernzerhof-sol(PBEsol)functionals qual-itatively reproduced the high pressure effects on the structural and electronic properties of CrBr3,with more accurately results obtained by PBEsol.The relative increase of the binding energy absolute value between the van der Waals layers by 75 times in the pressure range up to 60 GPa was evaluated.Band gap closure associ-ated with the semiconductor-metal transition was found at P=6o GPa,which is higher than the experimentally determined value.展开更多
基金Ostlin,L.Chioncel acknowledges financial support offered by the Augsburg Center for Innovative Technologies,and by the Deutsche Forschungsgemeinschaft(through the project TRR 80/F6).E.Burzo and D.P.Kozlenko work was supported by the Project nr.38/theme04-4-1121-2015/2020The N.O.Golosova,S.E.Kichanov and B.N.Savenko also acknowledge support from the grant RFBR17-02-00112.
文摘The crystal structure and magnetic properties of YCo5 compound have been studied by neutron diffraction,in the pressure range 0≤p≤7.2 GPa.The cobalt moments decrease with pressure,parallelly with anisotropic changes of lattice parameters.The experimental data are analyzed together with results from the combined Density Functional and Dynamical Mean-Field Theory.A rather good agreement between the experimentally determined and calculated values of cobalt moments is shown.Our scenario for the behavior of YCo5 under pressure,is the combined action of the Lifshitz transition with a strong local electron-electron interaction.
基金supported by the Vietnam National Foundation for Science and Technology Development(NAFOSTED)under grant number 103.02-2021.70.
文摘The evolution of the structural and electronic properties of the van der Waals layered ferromagnet CrBrs across the semiconductor-metal transition was investigated using X-ray powder diffraction and Raman spectroscopy at high pressures up to 38 GPa and by density functional theory(DFT)calculations at high pressures up to 120 GPa.The pressure behavior of the structural parameters and vibrational modes revealed a crossover from the quasi-two-dimensional system with weakly interacting atomic layers to the three-dimensional-like system with strongly interacting layers at P~15 GPa.This resulted in a significant modification of the pressure coefficients of the lattice parameters and interlayer distances.DFT calculations using first-principles generalized gradient ap-proximations of the Perdew-Burke-Ernzerhof(PBE)and Perdew-Burke-Ernzerhof-sol(PBEsol)functionals qual-itatively reproduced the high pressure effects on the structural and electronic properties of CrBr3,with more accurately results obtained by PBEsol.The relative increase of the binding energy absolute value between the van der Waals layers by 75 times in the pressure range up to 60 GPa was evaluated.Band gap closure associ-ated with the semiconductor-metal transition was found at P=6o GPa,which is higher than the experimentally determined value.
