Industrial Consultancy & Sponsored Research (IC&SR) , IIT Madras
Hetero-atom Induced Ferromagnetism in Antiferromagnetic Hematite
Technology Category/Market
Category – Advanced Material & Manufacturing
Applications – Nanobiosensors, batteries or giant magnetoresistance devices, data storage
Industry – Electronics, Materials Science Biomedical Engineering, Energy Storage Industry
Market – The global magnetic materials market is valued at USD 88.94 Billion in 2020 and expected to reach USD 164.68 Billion by 2027 with a CAGR of 9.2%.
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Problem Statement
- α-Fe2O3 (hematite) is an antiferromagnetic material, limiting its applications in magnetic fields despite its attractive properties.
- By incorporating carbon-based materials or other magnetic substances, the antiferromagnetic nature of α-Fe2O3 can be overcome, making it suitable for various technological applications in magnetism.
- The present invention proposes a method by creating a ferromagnetic composite for more efficient and less cumbersome than existing techniques, providing a promising solution for improving α-Fe2O3’s magnetic potential.
Technology
- The invention presents a single-step method for synthesizing ferromagnetic hematite iron oxide (α-Fe2O3) using either combustion or pyrolysis techniques.(Fig.1)
- For combustion synthesis, a composite admixture containing iron precursor(s) and heteroatom precursor(s) is heated to a predetermined temperature range of temperature range of 300 °C to 600 °C under an inert gas atmosphere. Subsequently, the admixture is exposed to atmospheric air.
- For pyrolytic synthesis, the same type of composite admixture is heated under an air atmosphere within a specific temperature range. The heat treatment duration is 2 to 3 hours.
- The method induces ferromagnetism by incorporating heteroatoms, possibly in the sites of crystal defects in α-Fe2O3, resulting in a high yield of magnetic α-Fe2O3 with strong magnetization.
Key Features/Value Proposition
- The resulting ferromagnetic hematite iron oxide has a rhombohedral crystal structure with specific oxygen and iron site defects, leading to magnetization of 7emu/g or greater.
- The oxygen occupancy at 18e site ranges from 1 to 0.499, and the iron occupancy at 12c site ranges from 1.005 to 0.978.
- The magnetization achieved is between 7-17 emu/g.
- The synthesized α-Fe2O3 has application in nanomagnetic devices, nanobiosensors, batteries, and magnetic field controlled photocatalytic reactors and biomedical applications.
- Potential use in targeted drug delivery, MRI, and magnetic separation techniques.
Questions about this Technology?
Contact for Licensing
smipm-icsr@icsrpis.iitm.ac.in
ipoffice2@iitm.ac.in
Research Lab
Prof. Ramaprabhu. S
Department of Physics
Intellectual Property
- IITM IDF Ref. 1765
- IN 201841038764
- PCT/IN2019/050751 – Published
Technology Readiness Level
TRL – 4
Technology validated in lab.