Magnetic Collapse in Fe₃Se₄ under High Pressure

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid State Chemistry

Background:

• Iron selenide (Fe3Se4) exhibits complex electronic and magnetic properties.
• Understanding its behavior under pressure is crucial for potential applications.

Purpose of the Study:

• To investigate the electronic structure and magnetic properties of Fe3Se4.
• To determine the effects of isotropic compression on its magnetic ordering and total magnetic moment.

Main Methods:

• Density functional theory (DFT) calculations were employed.
• Electronic structure and magnetic moments were computed.
• The impact of varying degrees of isotropic compression was simulated.

Main Results:

• Fe3Se4 is ferrimagnetic with distinct magnetic moments at different iron sites (M1=2.071μB, M2=-2.042μB).
• Compression non-monotonically affects the total magnetic moment and density of states at the Fermi level.
• Magnetic transitions occur: ferrimagnetic to ferromagnetic at 7% compression (5.0 GPa), and to paramagnetic at 14% compression (114 GPa).
• The system remains metallic under all simulated compression levels.

Conclusions:

• Isotropic compression significantly alters the magnetic state of Fe3Se4.
• Anisotropy in chemical bonding accelerates magnetic changes under pressure.
• Fe3Se4 transitions through ferrimagnetic, ferromagnetic, and paramagnetic states with increasing pressure.