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Rhodium Disk
Available Configurations
Properties common to all products in this list
| Thickness | Diameter |
|---|---|
| 0.006 mm to 0.5 mm | 4 mm to 50.8 mm |
Need custom configurations? Please contact us.
Key Features
Rhodium Disk at 99.9% purity is a precision-cut circular component in one of the rarest and most corrosion-resistant platinum group metals, offering the chemical inertness, high-temperature stability, and outstanding UV and visible reflectivity of rhodium in a defined geometry suited to optical, analytical, and high-temperature assemblies:
Exceptional Chemical Inertness — Resists Acids That Attack Platinum & Gold
Rhodium resists attack by virtually all acids and oxidizing environments, does not tarnish in air, and maintains its surface quality under conditions that degrade platinum, gold, and stainless steel — making it the material of choice for crucible liner disks, catalyst substrate disks, and electrochemical test specimens in aggressive media where no other precious metal disk is sufficiently inert.
Outstanding UV & Visible Reflectivity — Highest of Any Precious Metal
Rhodium's characteristic bright, silvery-white surface delivers higher UV and visible reflectivity than platinum, gold, or silver, making Rhodium Disk a natural choice for mirror substrates, reflectance calibration standards, and optical reference disks in UV and visible spectrophotometry where a chemically stable, high-reflectance surface must be maintained over extended use.
High Stiffness & Hardness in the Worked Condition for Dimensional Stability
Rhodium's high stiffness and hardness in the worked condition give Rhodium Disk good dimensional stability for precision optical and analytical applications — retaining its geometry under the mechanical and thermal stresses of calibration, instrumentation, and surface analysis use where softer precious metal disks would be susceptible to deformation.
High-Temperature Stability Without Oxidation or Tarnish
Rhodium does not oxidize at service temperatures and does not tarnish in air, maintaining its surface quality and chemical specification over extended high-temperature use — supporting its application in thermocouple target components and high-purity chemical process liners where sustained exposure to heat and reactive environments would degrade the surface of other disk materials.
Well-Characterized Precious Metal Surface for Research Applications
At 99.9% purity, Rhodium Disk provides a reproducible, well-characterized precious metal substrate for surface science, electrochemical characterization in aggressive media, and thin-film catalysis investigations — where its unusual catalytic selectivity and chemical inertness make it an experimentally useful reference material that other precious metal disks cannot replicate.
Industrial Applications
Rhodium Disk is used across optical metrology, analytical instrumentation, high-temperature processing, catalysis, and surface science research where no other disk material provides the same combination of chemical inertness, high reflectivity, and surface stability:
- ✦ Reflectance Calibration Standards & UV Mirror Substrates
- Used as reflectance calibration reference disks and UV mirror substrates in spectrophotometry and optical metrology, where rhodium's higher UV and visible reflectivity than any other precious metal, combined with its resistance to tarnish and chemical attack, ensures that the reference surface maintains its calibrated reflectance over extended analytical use without the degradation that would shift calibration values in platinum or silver reference standards.
- ✦ Thermocouple Target Components & High-Temperature Analytical Instrumentation
- Applied as thermocouple target components and substrate disks in high-temperature analytical instruments, where rhodium's resistance to oxidation at service temperatures and its surface stability under sustained thermal exposure ensure reliable, contamination-free performance in measurements where surface degradation of the target material would introduce systematic error.
- ✦ Crucible Liners for High-Purity Chemical Processes
- Used as crucible liner disks in high-purity chemical processes where rhodium's resistance to attack by hot concentrated acids and aggressive oxidizing environments — conditions that would corrode platinum, gold, or ceramic liners — ensures that the process stream is not contaminated by liner degradation products throughout extended high-temperature reactions.
- ✦ Catalyst Substrate Disks
- Applied as catalyst substrate disks in heterogeneous catalysis research and industrial catalytic processes, where rhodium's well-documented catalytic selectivity for specific oxidation, reduction, and coupling reactions — combined with its chemical inertness as a substrate material — supports both its direct use as a catalytic surface and as a support for deposited catalyst layers.
- ✦ Surface Science, Electrochemical Characterization & Thin-Film Catalysis Research
- Used in research as a reproducible, well-characterized precious metal substrate for surface analysis, electrochemical characterization in aggressive media, and thin-film catalysis investigations — where rhodium's unusual catalytic selectivity and resistance to surface contamination in harsh chemical environments make it an experimentally distinctive reference substrate for studies that platinum or gold disk alternatives cannot support.
Material Properties
| Element | Value |
|---|---|
| Atomic number | 45 |
| Crystal structure | Face centred cubic |
| Electronic structure | Kr 4d⁸ 5s¹ |
| Valences shown | 2,3,4,5,6 |
| Atomic weight( amu ) | 102.9055 |
| Thermal neutron absorption cross-section( Barns ) | 150 |
| Photo-electric work function( eV ) | 4.6 |
| Atomic radius - Goldschmidt( nm ) | 0.134 |
| Ionisation potential( No./eV ) | 1/ 7.46 |
| Ionisation potential( No./eV ) | 3/ 31.1 |
| Ionisation potential( No./eV ) | 2/ 18.1 |
| Element | Value |
|---|---|
| Material condition | Hard |
| Material condition | Soft |
| Poisson's ratio | 0.26 |
| Poisson's ratio | 0.26 |
| Bulk modulus( GPa ) | 276 |
| Bulk modulus( GPa ) | 276 |
| Tensile modulus( GPa ) | 379 |
| Tensile modulus( GPa ) | 379 |
| Hardness - Vickers( kgf mm⁻² ) | 300 |
| Hardness - Vickers( kgf mm⁻² ) | 120 |
| Tensile strength( MPa ) | 1380-2070 |
| Tensile strength( MPa ) | 690-760 |
| Yield strength( MPa ) | 69-275 |
| Element | Value |
|---|---|
| Electrical resistivity( µOhmcm ) | 4.7@20°C |
| Temperature coefficient( K⁻¹ ) | 0.0044@0-100°C |
| Thermal emf against Pt (cold 0C - hot 100C)( mV ) | 0.7 |
| Element | Value |
|---|---|
| Boiling point( C ) | 3727 |
| Density( gcm⁻³ ) | 12.4@20°C |
| Element | Value |
|---|---|
| Melting point( C ) | 1965 |
| Latent heat of evaporation( J g⁻¹ ) | 4800 |
| Latent heat of fusion( J g⁻¹ ) | 210 |
| Specific heat( J K⁻¹ kg⁻¹ ) | 244@25°C |
| Thermal conductivity( W m⁻¹ K⁻¹ ) | 150@0-100°C |
| Coefficient of thermal expansion( x10⁻⁶ K⁻¹ ) | 8.5@0-100°C |
Tolerances
| Thickness | <0.01mm | ±25% |
|---|---|---|
| Thickness | 0.01mm - 0.05mm | ±15% |
| Thickness | >0.05mm | ±10% |
| Diameter | ±0.5mm |