Revisiting MnSe : a Magnetic Semiconductor with Spin-Phonon coupling

TL;DR

This study reveals significant spin-phonon interactions in MnSe, a magnetic semiconductor, through Raman spectroscopy, uncovering its complex magnetism, phase transitions, and the interplay between magnetic behavior and phonon dynamics.

Contribution

It provides the first detailed analysis of spin-phonon coupling and phase transitions in pristine MnSe, highlighting its potential for spintronic applications.

Findings

Unconventional deviations in phonon self-energies around Neel temperature

P1 mode is highly sensitive to spin-phonon coupling

P2 mode responds to structural phase transition at 250 K

Abstract

Spin-phonon interactions in 2D magnetic materials are crucial in advancing next-generation spintronic devices. Therefore, identifying new materials with significant spin-phonon interactions is of great importance. In this context, MnSe, previously recognized as an exemplary non-layered p-type semiconductor emerges in this study as an intriguing material with notable spin-phonon characteristics. The complex magnetism in pristine MnSe, primarily dominated by antiferromagnetism with a weak ferromagnetic component, gives rise to both spontaneous and conventional exchange bias effects at low temperatures. In an effort to understand this intriguing magnetism, we conducted a detailed Raman spectroscopy study, which reveals unconventional deviations from the usual phonon anharmonicity around Neel temperature (170 K), in the self-energies of the P1, P2, and P3 modes. Notably, the P1 mode is most sensitive to spin-phonon coupling, while the P2 mode is particularly responsive to the structural phase transition at 250 K. Therefore, these findings provide comprehensive insights into the phase transitions of pristine MnSe, particularly highlighting the previously unobserved interplay between its magnetic behavior and phonon dynamics.