Observation of robust spin-phonon coupling and indication of hidden structural transition in the spin-driven ferroelectrics Mn4B_2O_9 (B= Nb, Ta)
Fuente:
arXiv
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Preprint |
| Published: |
2026
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866910013503569920 |
|---|---|
| author | Jana, Rajesh Garg, Alka Rao, Rekha Meier, Thomas |
| author_facet | Jana, Rajesh Garg, Alka Rao, Rekha Meier, Thomas |
| contents | We report detailed Raman spectroscopic and magnetic susceptibility studies on the spin-driven ferroelectric compounds Mn4Nb2O9 (MNO) and Mn4Ta2O9 (MTO). Both systems exhibit strong spin-phonon coupling below the short-range magnetic ordering temperature (T(sro)=223 K), followed by further renormalization of several Raman modes at the long-range magnetic ordering temperatures (TN = 120 K for MNO and 110 K for MTO). Pronounced anomalies in Raman mode frequencies and linewidths, along with the emergence of octahedral modes between Tsro and TN, indicate a possible low-symmetry structural transition, more evident in MNO and closely linked to magnetic ordering in MTO. Distinct low-temperature evolutions of Raman mode shift, linewidth, and integrated intensity in MNO and MTO highlight the role of the nonmagnetic B-site cation in tuning spin-lattice coupling, driven by differences in spin-orbit coupling and orbital hybridization between Nb5+ (4d) and Ta5+ (5d). By combining Raman spectroscopy with nuclear magnetic resonance, and diffuse reflectance spectroscopy, we further show that Mn-based systems possess a more distorted local structure than their Co analogues, while their electronic structures differ despite comparable band gaps. These results provide a comprehensive understanding of spin-lattice coupling in Mn- and Co-based A4B2O9 magnetoelectric systems. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2602_06311 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Observation of robust spin-phonon coupling and indication of hidden structural transition in the spin-driven ferroelectrics Mn4B_2O_9 (B= Nb, Ta) Jana, Rajesh Garg, Alka Rao, Rekha Meier, Thomas Materials Science We report detailed Raman spectroscopic and magnetic susceptibility studies on the spin-driven ferroelectric compounds Mn4Nb2O9 (MNO) and Mn4Ta2O9 (MTO). Both systems exhibit strong spin-phonon coupling below the short-range magnetic ordering temperature (T(sro)=223 K), followed by further renormalization of several Raman modes at the long-range magnetic ordering temperatures (TN = 120 K for MNO and 110 K for MTO). Pronounced anomalies in Raman mode frequencies and linewidths, along with the emergence of octahedral modes between Tsro and TN, indicate a possible low-symmetry structural transition, more evident in MNO and closely linked to magnetic ordering in MTO. Distinct low-temperature evolutions of Raman mode shift, linewidth, and integrated intensity in MNO and MTO highlight the role of the nonmagnetic B-site cation in tuning spin-lattice coupling, driven by differences in spin-orbit coupling and orbital hybridization between Nb5+ (4d) and Ta5+ (5d). By combining Raman spectroscopy with nuclear magnetic resonance, and diffuse reflectance spectroscopy, we further show that Mn-based systems possess a more distorted local structure than their Co analogues, while their electronic structures differ despite comparable band gaps. These results provide a comprehensive understanding of spin-lattice coupling in Mn- and Co-based A4B2O9 magnetoelectric systems. |
| title | Observation of robust spin-phonon coupling and indication of hidden structural transition in the spin-driven ferroelectrics Mn4B_2O_9 (B= Nb, Ta) |
| topic | Materials Science |
| url | https://arxiv.org/abs/2602.06311 |