Oxygen-vacancy-induced half-metallicity and enhanced ferromagnetism in Sr₂NiMnO₆: a DFT and Monte Carlo approach.
- 1Department of Electrical Engineering and Automation, Aalto University Finland.
- 2Department of Mathematics and Physics, North South University Dhaka Bangladesh [email protected] [email protected].
- 3Department of Electrical and Computer Engineering, North South University Dhaka Bangladesh.
Abstract
Realizing room-temperature spintronic functionality requires materials that maintain complete spin polarization at the Fermi level and robust ferromagnetic stability against thermal fluctuations. Here, Sr₂NiMnO₆ (SNMO) is introduced as a novel, high-performance double-perovskite candidate, and a mechanism to unlock its half-metallic potential via oxygen-vacancy (VO) engineering is uncovered. Using a combined DFT, lattice dynamics, and Monte Carlo approach, it is revealed that VO induction triggers a symmetry reduction (from I4/m to P1), driving a Ni-centered redox transition from a formal Ni⁴⁺ toward a Ni²⁺-like character, thereby evolving the electronic state from a spin-asymmetric semiconductor to a half-metal. The transition is further characterized by a substantial increase in the carrier effective mass (up to 1.235 m ₀), consistent with the emergence of localized polaronic character supporting the material's high-temperature stability and spin-selective transport. This structural-electronic coupling reconfigures the magnetic interaction from a weak superexchange-dominated regime toward an enhanced carrier-mediated exchange, consistent with, but not directly demonstrated by, the localized in-gap Ni states reported here, elevating the saturated magnetic moment to 6.00 µ B (from -2.97 µ B) and the Curie temperature to 480 K. These analyses establish a direct relationship between oxygen-vacancy formation, structural distortion, electronic reconstruction, and magnetic ordering in SNMO, highlighting oxygen-vacancy engineering as a strategy for tuning the spin-dependent properties of double perovskites for high-temperature spintronic applications.
Related
- Defect-induced ferromagnetism in undoped oxide thin films: the case of WO 3
- Oxygen Vacancy-Mediated Hydroxyl Radical Generation over Mn-Doped SrCoO3 Perovskite for Enhanced Steam Gasification of Graphite and Anti-Coking Performance
- Detection of Degraded Formulated BaTiO3 Induced by Oxygen Vacancy Migration Using Ultrasonic Attenuation
- Defect Diamond‐Like d 10 Metal Indium Selenium With Strong Second‐Harmonic Generation and Enhanced Laser‐Induced Damage Threshold
- Pu-Doping-Induced Weberite-like Local Motifs and Enhanced Immobilization in Gd2Zr2O7 Pyrochlore: A DFT + U Study
BibTeX
@article{apu2026oxygenvacancyinduced,
title = {{Oxygen-vacancy-induced half-metallicity and enhanced ferromagnetism in Sr₂NiMnO₆: a DFT and Monte Carlo approach.}},
author = {Rifat S Apu and Mohammad Kamrul Hasan and Anas Marsaad and Md Harunur Rashid and Rubaiyet I Haque},
journal = {RSC advances},
year = {2026},
month = oct,
doi = {10.1039/d6ra07202j},
url = {https://europepmc.org/article/MED/42899078},
note = {CC BY},
}
RIS
TY - JOUR
TI - Oxygen-vacancy-induced half-metallicity and enhanced ferromagnetism in Sr₂NiMnO₆: a DFT and Monte Carlo approach.
AU - Rifat S Apu
AU - Mohammad Kamrul Hasan
AU - Anas Marsaad
AU - Md Harunur Rashid
AU - Rubaiyet I Haque
PY - 2026
DA - 2026/10/19
JO - RSC advances
DO - 10.1039/d6ra07202j
UR - https://europepmc.org/article/MED/42899078
AB - Realizing room-temperature spintronic functionality requires materials that maintain complete spin polarization at the Fermi level and robust ferromagnetic stability against thermal fluctuations. Here, Sr₂NiMnO₆ (SNMO) is introduced as a novel, high-performance double-perovskite candidate, and a mechanism to unlock its half-metallic potential via oxygen-vacancy (VO) engineering is uncovered. Using a combined DFT, lattice dynamics, and Monte Carlo approach, it is revealed that VO induction triggers a symmetry reduction (from I4/m to P1), driving a Ni-centered redox transition from a formal Ni⁴⁺ toward a Ni²⁺-like character, thereby evolving the electronic state from a spin-asymmetric semiconductor to a half-metal. The transition is further characterized by a substantial increase in the carrier effective mass (up to 1.235 m ₀), consistent with the emergence of localized polaronic character supporting the material's high-temperature stability and spin-selective transport. This structural-electronic coupling reconfigures the magnetic interaction from a weak superexchange-dominated regime toward an enhanced carrier-mediated exchange, consistent with, but not directly demonstrated by, the localized in-gap Ni states reported here, elevating the saturated magnetic moment to 6.00 µ B (from -2.97 µ B) and the Curie temperature to 480 K. These analyses establish a direct relationship between oxygen-vacancy formation, structural distortion, electronic reconstruction, and magnetic ordering in SNMO, highlighting oxygen-vacancy engineering as a strategy for tuning the spin-dependent properties of double perovskites for high-temperature spintronic applications.
SN - 2046-2069
ER -