Magnesium Oxide, MgO
Magnesium oxide (MgO) is a wide-bandgap, rock-salt-structured ceramic oxide supplied as a high-purity sputtering target by Infinita Materials. Prized for its exceptional chemical stability, high electrical resistivity, and low lattice mismatch to a range of technologically important crystal systems, MgO thin films serve as insulating barriers, epitaxial buffer layers, and protective coatings across magnetics, optics, and electronics manufacturing.
| Purity (%) : | >99.9 |
| Dimensions : | Dia. 1”, Thick. 0.125” Dia. 2”, Thick. 0.25” |
Introduction to Magnesium Oxide
Magnesium oxide (MgO) crystallises in the cubic rock-salt structure (Fm-3m), featuring strong ionic bonding, high thermal stability, and a wide bandgap of approximately 7.8 eV. Its high resistivity, dielectric strength, chemical inertness, and optical transparency make it an excellent insulating and diffusion-barrier material. RF magnetron sputtering from ceramic MgO targets enables uniform, dense thin films with controlled thickness and stoichiometry. MgO is particularly important in magnetic tunnel junctions, where crystalline MgO acts as a tunnel barrier between ferromagnetic electrodes and enables high tunnelling magnetoresistance for MRAM and spintronic devices. Sputtered MgO films are also used as epitaxial buffer and seed layers, protective dielectric coatings, diffusion barriers, and speciality optical and electronic coatings.
FAQs
Question: How should MgO sputtering targets be handled?
Answer: MgO targets should be handled with care to avoid contamination. They must be stored in a dry environment and protected from direct exposure to moisture or high temperatures, which could degrade their properties.
Introduction to Magnesium Oxide
Magnesium oxide (MgO) crystallises in the cubic rock-salt structure (Fm-3m), featuring strong ionic bonding, high thermal stability, and a wide bandgap of approximately 7.8 eV. Its high resistivity, dielectric strength, chemical inertness, and optical transparency make it an excellent insulating and diffusion-barrier material. RF magnetron sputtering from ceramic MgO targets enables uniform, dense thin films with controlled thickness and stoichiometry. MgO is particularly important in magnetic tunnel junctions, where crystalline MgO acts as a tunnel barrier between ferromagnetic electrodes and enables high tunnelling magnetoresistance for MRAM and spintronic devices. Sputtered MgO films are also used as epitaxial buffer and seed layers, protective dielectric coatings, diffusion barriers, and speciality optical and electronic coatings.
Key Properties of Magnesium Oxide
| Property | Value | Significance |
|---|
| Crystal structure | Cubic rock-salt (NaCl-type), space group Fm-3m | Enables close lattice match to bcc ferromagnetic electrodes for coherent tunnelling in MTJ stacks |
| Lattice constant | ~4.21 angstroms | Determines epitaxial strain and orientation control when grown on Fe, CoFeB, or oxide substrates |
| Band gap | ~7.8 eV | Wide gap gives strong electrical insulation and low leakage current in ultrathin barrier films |
| Dielectric constant | ~9.8 (relative permittivity) | Supports use as a tunnel barrier and gate/buffer dielectric in thin-film devices |
| Electrical resistivity | >10^14 ohm-cm (bulk, insulating) | Requires RF or pulsed-DC sputtering rather than conventional DC due to target charging |
| Melting point | ~2852 C | High thermal stability supports target durability under sustained plasma bombardment |
| Thermal conductivity | ~30-48 W/m-K (dense polycrystalline to single crystal) | Aids heat dissipation across the target during high-power sputtering, reducing thermal shock risk |
| Magnetic type | Diamagnetic | Magnetically inert, preserving the switching behaviour of adjacent ferromagnetic layers in spintronic stacks |
Types & Grades of Magnesium Oxide
Magnesium Oxide targets are offered in standard catalogue sizes and grades, with custom purity, density, and geometry available for OEM and R&D deposition systems.
| Grade / Form | Typical Purity | Key Features / Uses |
|---|
| Standard catalogue disc | 99.9% (3N) | IN-Mg-01/IN-Mg-02 stock sizes for lab-scale MTJ, buffer layer, and coating development |
| High-purity electronic grade | 99.99% – 99.999% (4N-5N) | Reduced trace-metal and moisture content for tunnel barriers and low-leakage dielectric films |
| Large-format/custom disc | 99.9% – 99.99% | Rectangular and oversized round targets for production-scale magnetron sputtering systems |
| Bonded assembly | 99.9% – 99.99%, indium or elastomer bonded to Cu backing plate | Improves thermal transfer for high-power RF sputtering of this low-conductivity ceramic |
| Rotary/cylindrical target | 99.9% – 99.99% | Extends target utilisation and deposition uniformity for high-throughput in-line coating lines |
Applications of Magnesium Oxide
Sputtered films of Magnesium Oxide support demanding roles across research and production applications where this material’s specific structural, electronic, or optical properties are the key requirement.
| Industry | Application | Function |
|---|
| Spintronics/MRAM | Tunnel barrier in magnetic tunnel junctions (CoFeB/MgO/CoFeB) | Enables coherent tunnelling for high TMR ratio in MRAM cells and spin-torque devices |
| Data storage | Read-head sensor barrier layer | Provides insulating spacer with tunable resistance-area product for magnetic sensing |
| Oxide/nitride electronics | Epitaxial buffer/seed layer | Lattice-matched template for growth of superconducting oxides and GaN heterostructures |
| Display technology | Protective dielectric layer in AC plasma display panels | High secondary electron emission coefficient lowers discharge voltage and extends panel life |
| Optical coatings | Anti-reflective and protective IR-transparent films | Broadband transparency from near-UV to mid-IR with strong chemical durability |
| Refractory/protective coatings | Diffusion-barrier and passivation films on metals and ceramics | Chemical inertness and high melting point resist oxidation and reaction at elevated temperature |
Why Partner with Infinita Materials?
- Technical Depth: in-house quality control with ICP-MS and XRF purity verification, density measurement, and full certificates of analysis on every target.
- Global Logistics: reliable supply from single R&D-scale targets to production-line volumes, with established international shipping.
- Responsive Support: direct access to materials engineers for grade, bonding, and geometry selection, and process-compatibility questions.
Take the Next Step
Infinita Materials fabricates Magnesium Oxide sputtering targets engineered to the purity, density, and geometry your deposition process requires. Whether the requirement is a standard catalogue target or a custom size, purity, or bonded assembly, our team can help match the right specification to your deposition system. Request a quote or speak with our technical team to discuss your target specification.
Frequently Asked Questions
How should MgO sputtering targets be handled?
MgO targets should be handled with care to avoid contamination. They must be stored in a dry environment and protected from direct exposure to moisture or high temperatures, which could degrade their properties.
Magnesium Oxide, MgO
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