Lanthanum Hexaboride, also called LaB6 cathode, is an inorganic chemical of rare earth. With a melting point 2528 K, it is a refractory ceramic material, which is insoluble in water or hydrochloric acid and very stable in a vacuum.
The unique properties of lanthanum hexaboride crystals provide stable electron-emitting media with work functions near 2.70 eV. The low work function yields higher currents at lower cathode temperatures than tungsten, which means greater brightness, current at the beam focus, and longer life. Typically, LaB6 cathodes exhibit 10 times the brightness and 50 times the service life of tungsten cathodes. In electron microscope applications, these characteristics translate to more beam current in a smaller spot at the sample, improved resolution, and less frequent cathode replacement.
|Symbol||LaB6 cathode||Thermal Conductive||47 W/mK (20℃)|
|Cas No.||12008-21-8||Thermal Expansion||6.2 10-6K-1 (20-900℃)|
|Atomic Mass||203.78 g/mol||Electrical Resistance||ca.15 μΩ cm (20℃)|
|Density||4.72 g/cm3||Electrical Conductive||6.65×104 S/cm (20℃)|
|Melting Point||2528 K||Current Density||150 A/cm2 (1950℃)|
|Hardness||87.5 RA||Electron Emissivity||2.6 eV|
|Flexure Strength (σ)||200 Mpa||Fracture toughness (Kic)||3.0 MN/m3/2|
- Extended Life – Thousands of Hours in Clean Vacuum. Guaranteed Life (Measured in Surface Loss). Guaranteed Against Mounting Structure Failure.
- Exceptional Stability – Thermal/Chemical/Electrical. Precision Machined Carbon Mounting. High oprating temperature tolerance.
- High Brightness/Low Energy Spread – Oriented Single Crystal. Best-Quality/High-Purity Material.
- Accurate Microflats – Superior Optics/Controlled Source Size Standard Diameter Available.
-Thermionic emission (cathode)
-Plasma source for plasma-enhanced coating(PECVD)
-Vacuum electron beam welding machine
-Electron beam surface reforming device
-Electron beam lithography device
-Transmission electron microscope
-Scanning electron microscope
-Surface analysis device
-Radio therapy devices
|Short-term beam current stability % RMS||< 1||< 1|
|Typical service life (hr)||1,500+||1000+|
|Operating vacuum (torr)||10-7||10-7|
|Work function (eV)||~2.65||~2.70|
|Evaporation rate (g/cm2-sec)||1.6 x 10-9||2.2 x 10-9|
ACM’s high-quality lanthanum hexaboride cathode is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition.