Tuning the magnetic properties of the spin-split antiferromagnet MnTe through pressure

Abstract

The hexagonal antiferromagnet MnTe has attracted enormous interest as a prototypical example of a spin-compensated magnet in which the combination of crystal and spin symmetries lifts the spin degeneracy of the electron bands without the need for spin-orbit coupling, a phenomenon called non-relativistic spin splitting (NRSS). Subgroups of NRSS are determined by the specific spin-interconverting symmetry that connects the two opposite-spin sublattices. In MnTe, this symmetry is rotation, leading to the subgroup with spin splitting away from the Brillouin zone center, often called altermagnetism. MnTe also has the largest spontaneous magnetovolume effect of any known antiferromagnet, implying strong coupling between the magnetic moment and volume. This magnetostructural coupling offers a potential knob for tuning the spin-splitting properties of MnTe. Here, we use neutron diffraction with $\text{in situ}$ applied pressure to determine the effects of pressure on the magnetic properties of MnTe and further explore this magnetostructural coupling. We find that applying pressure significantly increases the Néel temperature but decreases the ordered magnetic moment. We explain this as a consequence of strengthened magnetic exchange interactions under pressure, resulting in higher $T_{\mathrm{N}}$, with a simultaneous reduction of the local moment of individual Mn atoms, described here via density functional theory. This reflects the increased orbital hybridization and electron delocalization with pressure. These results show that the magnetic properties of MnTe can be controlled by pressure, opening the door to improved properties for spintronic applications through tuning via physical or chemical pressure.

9 Pages, 6 figures, 1 table

References in corpus (12)

• Altermagnetism: spin-momentum locked phase protected by non-relativistic symmetries
• Broken Kramers' degeneracy in altermagnetic MnTe
• Spontaneous anomalous Hall effect arising from an unconventional compensated magnetic phase in a semiconductor
• Prediction of low-Z collinear and noncollinear antiferromagnetic compounds having momentum-dependent spin splitting even without spin-orbit coupling
• Coexistence of Anomalous Hall Effect and Weak Net Magnetization in Collinear Antiferromagnet MnTe
• Non-relativistic spin splitting in compensated magnets that are not altermagnets
• Real-space visualization of short-range antiferromagnetic correlations in a magnetically enhanced thermoelectric
• Interplay of altermagnetism and pressure in hexagonal and orthorhombic MnTe
• Femtosecond phononic coupling to both spins and charges in a room temperature antiferromagnetic semiconductor
• Clamp cell with $in$ $situ$ pressure monitoring for low-temperature neutron scattering measurements
• Origin of $A$-type antiferromagnetism and chiral split magnons in altermagnetic $\alpha$-MnTe
• Double-Exchange Enhanced Magnetic Blue-Shift of Mott Gaps

Cited by in corpus (5)

• Electric-Field-Controlled Altermagnetic Transition for Neuromorphic Computing
• Matter with apparent and hidden spin physics
• Multipole analysis of spin currents in altermagnetic MnTe
• Strain-tunable anomalous Hall effect in hexagonal MnTe
• Altermagnetism from the viewpoint of chemistry