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Filaments Overview

Denka M-3 LaB6 Cathodes

Advantages
The use of an electron beam enables not only observation of the submicron world (TEM’s SEM’s and X-ray microanalysers) but also processing with submicron precision (electron beam lithography systems). The optimum cathode material for use in these instruments would possess the following properties:
  • Low potential barrier (work function)
  • High melting point and stability at high temperatures
  • Low vapor pressure so as to reduce evaporation loss
  • Chemical stability
The relative drawbacks of tungsten cathodes are a work function of 4.7eV, insufficient beam current, and a short service life. LaB6 has a work function of 2.66eV – thus more easily emitting electrons – and is a relatively stable material, so it has been increasingly used as a material for cathodes instead of tungsten. Using LaB6 cathodes with TEMs and SEMs, even with the electron beam narrowed down, it is possible to obtain enough beam current to achieve better resolution and clear micrographs with less noise. The principle advantage, however, is that LaB6 can be used in a stable condition for a much longer time. Denka manufactures the purest, highest quality LaB6 crystals for use in their cathode tips.

Applications are:
  • SEM
  • TEM
  • X-ray Beam Analysis (EPMA)
  • Electron Beam Lithography

Benefits
  • High Brightness: A LaB6 beam is 10 times brighter than tungsten, has superior resolution, and features a wide range of acceleration voltages. It provides sharp, clear pictures, down to the smallest detail. The initial brightness of a Denka Model 3 cathode (1 x 106A/cm2.Str) is substantially better than that of competing, mini-vogel type cathodes (typically 5 x 105A/cm2.Str).
  • Long Life: Heat and vacuum are the final determinants of any cathode tip’s life, but at 1550°C and a vacuum of 10-7 Torr, a service life of about 500 hours can be expected.
  • Stability: Thanks to its simple and durable construction, every Denka Model 3 LaB6 Cathode offers a stability of better than 3% per hour at 1550°C.
  • Interchangeability: Denka Model 3 LaB6 cathodes are designed as direct replacements for tungsten filaments when a vacuum in the 10-7 range is provided.
Comparison of Tip Configurations Available with Denka M-3 LaB6 AEI style Cathodes
  Flat Tip Standard (Round) Tip Sharp Tip
  90° or 60° cone angle
20/40/60/100µm flat tip radius		 90° cone angle
15µm tip radius		 60° cone angle
5µm and 10µm tip radius
Brightness About 5 times that of tungsten
2-5 x 105 A/cm2 • Str		 About 10 times that of Tungsten
1 x 106 A/cm2 • Str		 Twice as bright as standard tips
2 x 106 A/cm2 • Str
Saturation Mono spot at about 1,400°C Mono spot at about 1,500°C Almost the same as standard tips
Crossover Large (11-13µm) Small (7-10µm) Small (7-10µm)
Angular Distribution Broad
3.3-4.2 x 10-2rad		 Sharp
1.6 x 10-2rad		 Sharp
1.6 x 10-2rad
Used Temperature Low Temperature High Temperature High Temperature
Lifetime Long life (usable at low temperatures, and crystallized
end changes slowly)		 Long life; shorter than flat tips Short
Operation Easy (thanks to its large spot size and broad adjusting range) Not so difficult Difficult (the point adjustment needed)
Stability High (invulnerable to thermal expansion or vibration) High Middle (vulnerable to thermal expansion or vibration, adjustment is sometimes necessary)
Technology Needed Ordinary High Very High

Dimensions for EM Filament Bases Tungsten/Lab6

Tantalum Wehnelt Apertures




Ordering Information for

Standard Denka M-3 LaB6 Cathodes
provided with a 90° cone angle and 15µm radius round tip.
 
denka jeol electron microscope Denka M-3 LaB6 Cathode for JEOL Instruments
(compatible with K-type filament base)

Prod # Description Unit Price Order / Quote
1450 Denka M-3 LaB6, Filament, LKS/90-15, standard tip each $1149.50
Qty:




denka philips electron microscope Denka M-3 LaB6 Cathode for FEI, Philips Instruments (Except XL-30)

Prod # Description Unit Price Order / Quote
1451 Denka M-3 LaB6, Filament, PH2/90-15, standard tip each $1215.00
Qty:




denka amray electron microscope Denka M-3 LaB6 Cathode for AMRAY Instruments
(except 1200 Series)

Prod # Description Unit Price Order / Quote
1452 Denka M-3 LaB6 Filament, AM/90-15, standard tip each $1220.00
Qty:




denka cambridge electron microscope Denka M-3 LaB6 Cathode AEI base for Cambridge (except S2A and S4-10), Camscan, Electroscan, Leica, LEO and Zeiss (EVO®) Instruments

Prod # Description Unit Price Order / Quote
1453 Denka M-3 LaB6 Filament, CA/90-15, standard tip each $1042.00
Qty:




denka hitachi electron microscope Denka M-3 LaB6 Cathode for Hitachi Instruments

Prod # Description Unit Price Order / Quote
1454 Denka M-3 LaB6 Filament, H2/90-15, standard tip each $1063.30
Qty:




Denka M-3 LaB6 Cathode Denka M-3 LaB6 Cathode for ZEISS/LEO TEM, Zeiss DSM SEMs, or Tescan SEMs

Prod # Description Unit Price Order / Quote
1449 Denka M-3 LaB6, Filament, Z2/90-15, standard tip each $1042.00
Qty:

 

 

Ordering Information for

Denka M-3 LaB6 Cathodes Sharp and Flat Tips
AMRAY (Except 1200 Series)

Prod # Description Unit Price Order / Quote
1455 Denka LaB6 Filament, AM/60-5, Sharp Tip each $1238.50
Qty:
1456 Denka LaB6 Filament, AM/60-10, Sharp Tip each 1208.00
Qty:
1457 Denka LaB6 Filament, AM/60-20, Flat Tip each 1299.00
Qty:
1458 Denka LaB6 Filament, AM/60-40, Flat Tip each 1424.00
Qty:
1459 Denka LaB6 Filament, AM/60-60, Flat Tip each 1548.50
Qty:
1460 Denka LaB6 Filament, AM/60-100, Flat Tip each 1798.00
Qty:
1461 Denka LaB6 Filament, AM/90-20, Flat Tip each 1121.00
Qty:
1462 Denka LaB6 Filament, AM/90-40, Flat Tip each 1245.50
Qty:
1463 Denka LaB6 Filament, AM/90-60, Flat Tip each 1370.00
Qty:
1464 Denka LaB6 Filament, AM/90-100, Flat Tip each 1619.00
Qty:
Numbers represent: Cone Angle - Tip Radius in µm




AEI style base for Cambridge, Leica, LEO, Zeiss (EVO®), CamScan

Prod # Description Unit Price Order / Quote
1465 Denka LaB6 Filament, CA/60-5, Sharp Tip each $1239.00
Qty:
1466 Denka LaB6 Filament, CA/60-10, Sharp Tip each 1208.00
Qty:
1467 Denka LaB6 Filament, CA/60-20, Flat Tip each 1299.00
Qty:
1468 Denka LaB6 Filament, CA/60-40, Flat Tip each 1424.00
Qty:
1469 Denka LaB6 Filament, CA/60-60, Flat Tip each 1548.50
Qty:
1470 Denka LaB6 Filament, CA/60-100, Flat Tip each 1798.00
Qty:
1471 Denka LaB6 Filament, CA/90-20, Flat Tip each 1121.00
Qty:
1472 Denka LaB6 Filament, CA/90-40, Flat Tip each 1245.50
Qty:
1473 Denka LaB6 Filament, CA/90-60, Flat Tip each 1370.00
Qty:
1474 Denka LaB6 Filament, CA/90-100, Flat Tip each 1619.00
Qty:
Numbers represent: Cone Angle - Tip Radius in µm




Hitachi

Prod # Description Unit Price Order / Quote
1475 Denka LaB6 Filament, H2/60-5, Sharp Tip each $1239.00
Qty:
1476 Denka LaB6 Filament, H2/60-10, Sharp Tip each 1208.00
Qty:
1477 Denka LaB6 Filament, H2/60-20, Flat Tip each 1299.00
Qty:
1478 Denka LaB6 Filament, H2/60-40, Flat Tip each 1424.00
Qty:
1479 Denka LaB6 Filament, H2/60-60, Flat Tip each 1548.50
Qty:
1480 Denka LaB6 Filament, H2/60-100, Flat Tip each 1798.00
Qty:
1481 Denka LaB6 Filament, H2/90-20, Flat Tip each 1121.00
Qty:
1482 Denka LaB6 Filament, H2/90-40, Flat Tip each 1245.50
Qty:
1483 Denka LaB6 Filament, H2/90-60, Flat Tip each 1370.00
Qty:
1484 Denka LaB6 Filament, H2/90-100, Flat Tip each 1619.00
Qty:
Numbers represent: Cone Angle - Tip Radius in µm




ISI, ABT, Topcon

Prod # Description Unit Price Order / Quote
1492 Denka LaB6 Filament, ISS/90-20, Flat Tip each $1022.00
Qty:
1493 Denka LaB6 Filament, ISS/90-40, Flat Tip each 1022.00
Qty:
1500 Denka LaB6 Filament, ISS/60-40, Flat Tip each 1022.00
Qty:
Numbers represent: Cone Angle - Tip Radius in µm




JEOL (Compatible with K-type Filament Base)

Prod # Description Unit Price Order / Quote
1507 Denka LaB6 Filament, LKS/60-20, Flat Tip each $1299.00
Qty:
1508 Denka LaB6 Filament, LKS/60-40, Flat Tip each 1424.00
Qty:
1509 Denka LaB6 Filament, LKS/60-60, Flat Tip each 1548.50
Qty:
1510 Denka LaB6 Filament, LKS/60-100, Flat Tip each 1798.00
Qty:
1511 Denka LaB6 Filament, LKS/90-20, Flat Tip each 1121.00
Qty:
1512 Denka LaB6 Filament, LKS/90-40v, Flat Tip each 1245.50
Qty:
1513 Denka LaB6 Filament, LKS/90-60, Flat Tip each 1370.00
Qty:
1514 Denka LaB6 Filament, LKS/90-100, Flat Tip each 1619.00
Qty:
1515 Denka LaB6 Filament, LKSH60, 10µm Sharp Tip, TEM only each 1232.70
Qty:
1516 Denka LaB6 Filament, LKSH60S, 5µm Sharp Tip, TEM only each 1264.50
Qty:
Numbers represent: Cone Angle - Tip Radius in µm




FEI, Philips (Except XL-30)

Prod # Description Unit Price Order / Quote
1517 Denka LaB6 Filament, PH2/60-5, Sharp Tip each $1239.00
Qty:
1518 Denka LaB6 Filament, PH2/60-10, Sharp Tip each 1208.00
Qty:
1519 Denka LaB6 Filament, PH2/60-20, Flat Tip each 1299.00
Qty:
1520 Denka LaB6 Filament, PH2/60-40, Flat Tip each 1424.00
Qty:
1521 Denka LaB6 Filament, PH2/60-60, Flat Tip each 1548.50
Qty:
1522 Denka LaB6 Filament, PH2/60-100, Flat Tip each 1798.00
Qty:
1523 Denka LaB6 Filament, PH2/90-20, Flat Tip each 1121.00
Qty:
1524 Denka LaB6 Filament, PH2/90-40, Flat Tip each 1245.50
Qty:
1525 Denka LaB6 Filament, PH2/90-60, Flat Tip each 1485.00
Qty:
1526 Denka LaB6 Filament, PH2/90-100, Flat Tip each 1619.00
Qty:
Numbers represent: Cone Angle - Tip Radius in µm

 

ZEISS/LEO, Tescan

Prod # Description Unit Price Order / Quote
1448 Denka LaB6 Filament, Z2/90-20, Flat Tip each $1121.00
Qty:
Numbers represent: Cone Angle - Tip Radius in µm


Dimensions for EM Filament Bases (for Tungsten/Lab6) Filaments

Base Type Diameter of Ceramic disc
in mm		 Diameter of Pins
in mm		 Center Distance of Pins
in mm
AEI 12.0 1.0 6.45
FEI/PHILIPS 26.0 1.0 5.0
JEOL K-type 28.0 1.2 8.0
HITACHI S-type 9.8 1.2 2.7
ZEISS (DSM & TEM)
LEO (1450 & TEM)
TESCAN		 19.8 1.0 5.0
AMRAY (except 1200) 26.1 1.0 5.0
ISI/ABT/TOPCON
2 pins		 23.3 1.2 11.9
ISI/ABT/TOPCON 23.4 1.2 12.0