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Molybdenum Foil (Light Tight)
Available Configurations
Properties common to all products in this list
| Purity | Thickness | Width | Length | Temper ⓘ | Surface Finish | Other Variant |
|---|---|---|---|---|---|---|
| 99.9% (3N) 99.95% (3N5) | 0.004 mm (foil) to 12.7 mm (plate) | 8.25 mm to 610 mm | 8.25 mm to 1000 mm | Annealed Stress Relieved As Rolled |
Polished on both sides | Non Light Tested |
Need custom configurations? Please contact us.
Key Features
Molybdenum Foil (Light Tight) is a pinhole-free refractory metal foil available in 99.9% and 99.95% purities, blocking all visible and near-visible light transmission while delivering the thermal stability, dimensional rigidity, and ultra-high vacuum compatibility that standard light-tight foils cannot provide:
Pinhole-Free Light Barrier with High-Temperature Stability (Melting Point 2,617 °C)
With a melting point of 2,617 °C, Molybdenum Foil (Light Tight) maintains both its optical barrier function and structural integrity in high-temperature and UHV environments where copper or aluminum light-tight foils would oxidize, distort, or contaminate sensitive systems — providing a reliable pinhole-free optical barrier capable of service through vacuum bake-out procedures and sustained elevated-temperature operation.
Greater Rigidity Than Standard Light-Tight Foils (Tensile Strength 485–690 MPa, Vickers Hardness 200–250 kgf/mm²)
With tensile strength of 485–690 MPa and Vickers hardness of 200–250 kgf/mm², Molybdenum Foil (Light Tight) provides a resistance to mechanical deformation that thinner, softer light-tight foils cannot match — important in precision aperture masks, beam stops, and shielding baffles where dimensional stability of the optical barrier geometry is as critical as its opacity.
Purity 99.9% & 99.95% for Application-Specific Selection
The 99.9% grade suits demanding industrial shielding, furnace radiation barriers, and beamline components where refractory performance and pinhole-free construction are the primary requirements; the 99.95% grade reduces trace impurity levels for surface-sensitive UHV applications, photoemission spectroscopy chambers, and high-specification research assemblies where material purity at the foil surface is an experimental variable.
Ultra-High Vacuum Compatibility & Low Outgassing
Extremely low outgassing behavior under vacuum ensures Molybdenum Foil (Light Tight) maintains vacuum cleanliness and optical integrity in UHV systems, beamline components, and vacuum bake-out procedures — combining the light-tight barrier function with the vacuum compatibility required in photoemission, surface physics, and electron microscopy environments where outgassing from standard foil alternatives would be unacceptable.
Thermal Conductivity of 138 W/m·K & Low CTE (5.1 × 10⁻⁶ K⁻¹)
A thermal conductivity of 138 W/m·K supports use in assemblies where the shielding foil must also conduct heat, while a CTE of 5.1 × 10⁻⁶ K⁻¹ ensures that the foil maintains dimensional accuracy through repeated thermal cycling — critical in furnace radiation shields and detector housings where thermal distortion of the barrier would compromise optical isolation.
Compatible with Aggressive Cleaning Protocols & Vacuum Bake-Out
Molybdenum Foil (Light Tight) is the material of choice when a light-tight barrier must survive aggressive cleaning protocols, solvent exposure, or vacuum bake-out procedures that would degrade copper, aluminum, or polymer-based light-tight foil alternatives — providing a chemically robust, thermally stable optical barrier for precision instrument and accelerator environments.
Industrial Applications
Molybdenum Foil (Light Tight) is used across UHV systems, synchrotron and particle physics facilities, electron microscopy, spectroscopy, and furnace technology wherever a light-tight barrier must also survive elevated temperatures, vacuum bake-out, or aggressive cleaning conditions that degrade standard foil alternatives:
- ✦ Cryogenic Radiation Baffles in UHV Systems
- Employed as cryogenic radiation baffles in UHV systems, where extremely low outgassing behavior and compatibility with vacuum bake-out procedures ensure clean vacuum and complete optical isolation. The 99.95% grade is specified for photoemission spectroscopy and surface physics instrumentation where trace impurity levels at the foil surface are experimental variables; the 99.9% grade suits general UHV baffling applications where industrial-grade purity is sufficient.
- ✦ Beamline Shielding Components in Synchrotron & Particle Physics Facilities
- Used as beamline shielding components in synchrotron radiation and particle physics facilities, where a melting point of 2,617 °C, vacuum compatibility, and dimensional rigidity of 485–690 MPa tensile strength ensure that the light-tight barrier maintains its optical integrity and geometric accuracy under the radiation, thermal, and vacuum bake-out conditions of accelerator facility operation.
- ✦ Furnace Radiation Shields Requiring Light Exclusion & High-Temperature Service
- Applied as furnace radiation shields where both light exclusion and sustained high-temperature service are required simultaneously, with a melting point of 2,617 °C and a CTE of 5.1 × 10⁻⁶ K⁻¹ ensuring that the shield maintains its pinhole-free optical barrier function without dimensional distortion through the thermal cycling of high-temperature furnace operation.
- ✦ Detector Housings in Spectroscopy & Electron Microscopy
- Used in detector housings for spectroscopy and electron microscopy instruments, where Molybdenum Foil (Light Tight) provides a rigid, vacuum-compatible enclosure material that excludes ambient light from detector assemblies and survives the aggressive cleaning and vacuum preparation protocols of precision analytical instrument maintenance — where copper or aluminum alternatives would degrade or contaminate.
- ✦ Research: Light-Tight Barriers in High-Temperature & UHV Experimental Assemblies
- Specified in research as the light-tight barrier material of choice when the assembly must survive elevated temperatures, aggressive chemical cleaning, or vacuum bake-out that would degrade standard foil alternatives. The 99.95% grade is selected where material purity is an experimental variable; the 99.9% grade suits applications where refractory performance and pinhole-free construction are the defining requirements.
Material Properties
| Element | Value |
|---|---|
| Atomic number | 42 |
| Crystal structure | Body centred cubic |
| Electronic structure | Kr 4d⁵ 5s¹ |
| Valences shown | 2, 3, 4, 5, 6 |
| Atomic weight( amu ) | 95.94 |
| Thermal neutron absorption cross-section( Barns ) | 2.65 |
| Photo-electric work function( eV ) | 4.2 |
| Natural isotope distribution( Mass No./% ) | 95/ 15.9 |
| Natural isotope distribution( Mass No./% ) | 96/ 16.7 |
| Natural isotope distribution( Mass No./% ) | 98/ 24.1 |
| Natural isotope distribution( Mass No./% ) | 97/ 9.6 |
| Natural isotope distribution( Mass No./% ) | 92/ 14.8 |
| Natural isotope distribution( Mass No./% ) | 94/ 9.3 |
| Natural isotope distribution( Mass No./% ) | 100/ 9.6 |
| Atomic radius - Goldschmidt( nm ) | 0.14 |
| Ionisation potential( No./eV ) | 2/ 16.15 |
| Ionisation potential( No./eV ) | 5/ 61.2 |
| Ionisation potential( No./eV ) | 68 |
| Ionisation potential( No./eV ) | 1/ 7.10 |
| Ionisation potential( No./eV ) | 3/ 27.2 |
| Ionisation potential( No./eV ) | 4/ 46.4 |
| Element | Value |
|---|---|
| Material condition | Hard |
| Material condition | Soft |
| Poisson's ratio | 0.293 |
| Poisson's ratio | 0.293 |
| Bulk modulus( GPa ) | 261.2 |
| Bulk modulus( GPa ) | 261.2 |
| Tensile modulus( GPa ) | 324.8 |
| Tensile modulus( GPa ) | 324.8 |
| Hardness - Vickers( kgf mm⁻² ) | 250 |
| Hardness - Vickers( kgf mm⁻² ) | 200 |
| Tensile strength( MPa ) | 485-550 |
| Tensile strength( MPa ) | 620-690 |
| Yield strength( MPa ) | 550 |
| Yield strength( MPa ) | 415-450 |
| Element | Value |
|---|---|
| Electrical resistivity( µOhmcm ) | 5.7@20°C |
| Superconductivity critical temperature( K ) | 0.915 |
| Temperature coefficient( K⁻¹ ) | 0.00435@0-100°C |
| Thermal emf against Pt (cold 0C - hot 100C)( mV ) | 1.45 |
| Element | Value |
|---|---|
| Boiling point( C ) | 4612 |
| Density( gcm⁻³ ) | 10.22@20°C |
| Element | Value |
|---|---|
| Melting point( C ) | 2617 |
| Latent heat of evaporation( J g⁻¹ ) | 6153 |
| Latent heat of fusion( J g⁻¹ ) | 290 |
| Specific heat( J K⁻¹ kg⁻¹ ) | 251@25°C |
| Thermal conductivity( W m⁻¹ K⁻¹ ) | 138@0-100°C |
| Coefficient of thermal expansion( x10⁻⁶ K⁻¹ ) | 5.1@0-100°C |
Tolerances
| Thickness | <0.01mm | ±25% |
|---|---|---|
| Thickness | 0.01mm - 0.05mm | ±15% |
| Thickness | >0.05mm | ±10% |
| Linear dimension | <100mm | ±1mm |
| Linear dimension | >=100mm | +2 / -1% |