Lanthanum Hexaboride Cathode Description
Lanthanum Hexaboride Cathode(LaB6 cathode, also called lanthanum boride cathode and LaB6 cathode) is an inorganic chemical. With a melting point of 2528 K, LaB6 cathode is a refractory ceramic material, which is insoluble in water or hydrochloric acid and very stable in a vacuum. LaB6 cathode Stoichiometric samples are colored intensely purple-violet, while boron-rich ones (above LaB6.07) are blue. Ion bombardment changes its color from purple to emerald green. LaB6 cathode is a superconductor with a relatively low transition temperature of 0.45 K.
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, or 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.
Lanthanum Hexaboride Cathode Specification
|
Product
|
Lanthanum Hexaboride
|
Structure
|
Polycrystalline
|
|
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
|
6.65x104 S/cm (20℃)
|
|
Melting Point
|
2528 K
|
Currency 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
|
Chemical Composition
|
LaB6 (% min.)
|
|
99.9%
|
|
B(% min.)
|
|
31%
|
|
Rare Earth Impurities
|
Non-RE Impurities
|
|
Ce
|
<120ppm
|
Fe
|
<250ppm
|
|
Pr
|
<150ppm
|
Si
|
<100ppm
|
|
Nd
|
<180ppm
|
Ca
|
<90ppm
|
|
Sm
|
<112ppm
|
C
|
<300ppm
|
|
Y
|
<250ppm
|
Mg
|
<100ppm
|
|
|
|
Ti
|
<100ppm
|
Lanthanum Hexaboride Cathode Applications
* 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
* Radiotherapy devices
Lanthanum Hexaboride Cathode Packing
SAMs’ LaB6 cathode is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition.
Prototyping service is also available for other ceramics material
Alumina
Aluminum Nitride
Boron Nitride
Silicon Carbide
Silicon Nitride
Zirconia
Related articles:
What is Lanthanum Hexaboride Electrode
