Lanthanum Hexaboride (LaB6) Cathode
Lanthanum Hexaboride (LaB6) cathodes usually show 10 times the brightness and 50 times the service life of tungsten cathodes. In electron microscopy applications, these characteristics can convert more electron beam currents on smaller spots of the sample, improve resolution, and reduce the frequency of cathode replacement.
The unique properties of lanthanum hexaboride crystals provide a stable electron emission medium with a work function close to 2.70 eV. The low work function produces a higher current at a lower cathode temperature than tungsten, which means greater brightness or current at the beam focus, and a longer LaB6 cathode life.
We provide LaB6 cathode with customized dimensions; regular purity is 99.5%.
Lanthanum Hexaboride Cathode Material Specifications
|Symbol||LaB6||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 Conductivity||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|
Lanthanum Hexaboride Cathode Advantages
Clean thousands of hs in a vacuum. Guaranteed life (in units of surface loss). Ensure that there will be no installation structural failures.
Thermal / Chemical / Electrical. Precision-machined carbon fiber installation. High temperature resistance.
-High brightness / low energy consumption
Oriented single crystal. Best quality / high purity material.
-Precise miniature shoes
Provide excellent optical components / controlled light sce size standard diameter.
LaB6 Cathode vs. CeB6 Cathode
|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|
Packing of Lanthanum Boride
Lanthanum Hexaboride Cathode is carefully handled to minimize damage during storage and transportation and to preserve the quality of products in their original condition. Vacuum packing is use for some of ceramic parts.