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.


  • 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

  1. 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.
  2. 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.
  3. The magnetization achieved is between 7-17 emu/g.
  4. The synthesized α-Fe2O3 has application in nanomagnetic devices, nanobiosensors, batteries, and magnetic field controlled photocatalytic reactors and biomedical applications.
  5. Potential use in targeted drug delivery, MRI, and magnetic separation techniques.

Questions about this Technology?

Contact for Licensing

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.

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