Alumina-Coated Iron Oxide Powder (Al2O3@Fe3O4)
Al2O3@Fe3O4 powder pairs a magnetic iron-oxide core with a hard, chemically inert alumina shell, giving an electrically insulated magnetic particle for composite and dielectric-filler applications.
Insulating shellCoating Content
~80 nmParticle Size Range
Custom Made-to-OrderGrade, Size & Quantity
WorldwideExport Shipping
Alumina-Coated Iron Oxide Powder — Grades & Specifications
Alumina-Coated Iron Oxide Powder (Al2O3@Fe3O4) powder is supplied across a range of grades, particle sizes and coating ratios. The options below are typical; specify your target values in the request form and we will confirm availability, lead time and pricing.
| Material | Alumina-Coated Iron Oxide Powder (Al2O3@Fe3O4) |
|---|---|
| Category | Ceramic/Oxide-Coated Powder |
| Core material | Magnetite (iron oxide) (CAS 1317-61-9) |
| Coating / shell material | Aluminum oxide (alumina) (CAS 1344-28-1) |
| Coating content | Shell thickness/wt% varies by grade and is confirmed on request; the alumina layer functions as a thin electrically insulating shell |
| Particle size | Approximately 80 nm APS on commercial nanopowder grade |
| Morphology | Core-shell nanoparticle structure |
| Appearance | Dark powder (typical of magnetite-based nanopowders) |
| Electrical Insulation | The alumina shell electrically insulates the magnetic core, reducing eddy-current losses and improving oxidation/corrosion resistance versus uncoated magnetite — the same rationale used for alumina-insulated soft-magnetic composite powders |
| Typical applications | Soft Magnetic Composite (SMC) Cores, Magnetic Separation & Adsorption Media, Catalyst Supports, Biomedical & MRI Contrast Platforms |
Applications by Industry
Soft Magnetic Composite (SMC) CoresInsulated magnetic particles reduce eddy-current loss in inductor and motor cores.
Magnetic Separation & Adsorption MediaChemically stabilized magnetic core for solid-liquid separation processes.
Catalyst SupportsAlumina shell provides a stable, high-surface-area support for immobilizing catalytic species on a magnetically recoverable core.
Biomedical & MRI Contrast PlatformsInsulated magnetic core as a chemically inert base for further bioconjugation.
Magnetic Fluids & Damping MediaUsed in magnetic fluid and precision damping applications.
Corrosion-Resistant Magnetic FillersAdditive in composites needing both magnetism and oxidation resistance.
Particle Size & Mesh Conversion
Reference for converting between US mesh and microns/millimetres. Figures are nominal sieve openings and may vary slightly by standard.
| Mesh (US) | Micron (µm) | mm | Inch | Remarks |
|---|---|---|---|---|
| 3 | 6730 | 6.730 | 0.2650 | |
| 4 | 4760 | 4.760 | 0.1870 | |
| 5 | 4000 | 4.000 | 0.1570 | |
| 6 | 3360 | 3.360 | 0.1320 | |
| 7 | 2830 | 2.830 | 0.1110 | |
| 8 | 2380 | 2.380 | 0.0937 | |
| 10 | 2000 | 2.000 | 0.0787 | |
| 12 | 1680 | 1.680 | 0.0661 | |
| 14 | 1410 | 1.410 | 0.0555 | |
| 16 | 1190 | 1.190 | 0.0469 | |
| 18 | 1000 | 1.000 | 0.0394 | |
| 20 | 841 | 0.841 | 0.0331 | |
| 25 | 707 | 0.707 | 0.0278 | |
| 30 | 595 | 0.595 | 0.0234 | |
| 35 | 500 | 0.500 | 0.0197 | |
| 40 | 420 | 0.420 | 0.0165 | |
| 45 | 354 | 0.354 | 0.0138 | |
| 50 | 297 | 0.297 | 0.0117 | |
| 60 | 250 | 0.250 | 0.0098 | |
| 70 | 210 | 0.210 | 0.0083 | |
| 80 | 177 | 0.177 | 0.0070 | |
| 100 | 149 | 0.149 | 0.0059 | |
| 120 | 125 | 0.125 | 0.0049 | |
| 140 | 105 | 0.105 | 0.0041 | |
| — | 100 | 0.100 | 0.0039 | Sand |
| 170 | 88 | 0.088 | 0.0035 | |
| 200 | 74 | 0.074 | 0.0029 | |
| — | 70 | 0.070 | 0.0027 | |
| 230 | 63 | 0.063 | 0.0024 | Human hair |
| — | 55 | 0.055 | 0.00217 | |
| 270 | 53 | 0.053 | 0.0021 | |
| — | 50 | 0.050 | 0.00197 | |
| 325 | 44 | 0.044 | 0.0017 | |
| — | 40 | 0.040 | 0.00157 | |
| 400 | 37 | 0.037 | 0.0015 | |
| 550 | 25 | 0.025 | 0.00099 | |
| 625 | 20 | 0.020 | 0.00079 | |
| 1200 | 12 | 0.012 | 0.0005 | |
| 1250 | 10 | 0.010 | 0.000394 | |
| — | 7 | 0.007 | 0.000276 | |
| 2500 | 5 | 0.005 | 0.000197 | |
| 4800 | 3 | 0.003 | 0.000118 | |
| 5000 | 2.5 | 0.0025 | 0.000099 | Bacteria (approx.) |
| 12000 | 1 | 0.001 | 0.0000394 |
Information Required for Quotation
- Grade or type
- Particle size (micron or mesh)
- Coating content / core-shell ratio
- Quantity
- Application environment
- Required delivery country
Lead time depends on grade, particle size, quantity and processing requirements. Export availability can be reviewed based on destination country and material type. A Certificate of Analysis can be provided on request.
Request a Quote or Custom Order
Tell us your grade, particle size and quantity. We typically reply within one business day.
Frequently Asked Questions
What is the coating content of Alumina-Coated Iron Oxide Powder?
Shell thickness/wt% varies by grade and is confirmed on request; the alumina layer functions as a thin electrically insulating shell Other coating ratios can be reviewed on request depending on your application and quantity.
What particle sizes can you supply?
Approximately 80 nm APS on commercial nanopowder grade Mesh-based requirements are also accepted; a mesh-to-micron conversion reference is provided on the page.
Can Alumina-Coated Iron Oxide Powder be made to custom specifications?
Yes. Alumina-Coated Iron Oxide Powder is produced to order — core/shell ratio, particle size, morphology and packaging can be customized to your specification. Select “Custom Order” in the request form and provide your target values.
What is the minimum order quantity (MOQ)?
Order quantity is flexible and small quantities and prototype requests are welcome. Please state your required quantity in the form for an accurate quotation.
Can you export and ship Alumina-Coated Iron Oxide Powder internationally?
Yes, export inquiries are welcome. Availability and shipping are reviewed based on destination country, grade and quantity.
Do you provide a Certificate of Analysis (COA) or technical data?
A Certificate of Analysis and technical data can be provided on request for supplied lots.
Related Products
Request a Quote for Alumina-Coated Iron Oxide Powder
Send us your grade, particle size, quantity and application. We will review availability, quotation and lead time. Small quantities, prototypes and custom made-to-order specifications are welcome.