MBE Components, High Temperature Effusion Cell HTEZ-W

HTEZ-W

High Temperature Effusion Cell

HTEZ-W
  • Compatible with most MBE systems

  • Various crucible materials; crucible capacity 10 cm³

  • No ceramic insulation parts in hot area

  • Free-standing thick tungsten wire filament

  • Clean operation in UHV up to 2000°C

  • High reliability and long lifetime

  • Water cooled current contacts

HTEZ-W 40-10-32 High Temperature Effusion Cell on DN40CF (O.D.2.75") flange

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The High Temperature Effusion Cells HTEZ are designed for clean UHV operation up to 1900°C. This is accomplished by a self-supporting tungsten filament. 

Equipped with a free-standing filament of thick tungsten wire, the model HTEZ-W is capable of reaching 2000°C or even more. The main parts of the heating system are shown in the figure on the right.

In contrast to the HTS sources, HTEZ-W cells predominantly heat the crucible from the side. The deep crucible design allows operation in angled port positions, combining large capacity with high temperature operation.

Like in the standard WEZ heating system, only selected refractory metals are used in the hot zone. On account of the elevated operating temperatures, the filaments are made of tungsten.  

While insulating PBN ceramic parts are fully shielded by tantalum plates to prevent outgassing during operationin in HTEZ cells, the HTEZ-W cells work completely without any additional ceramic insulation.

HTEZ-W cells are highly efficient, enable a very reproducible temperature measurement and allow precise adjustment as the thermocouple measuring point is close to the crucible.

HTEZ wire heater
Main parts of the HTEZ-W schematic

Well-designed tungsten filaments have proved to be very stable, thus safeguarding a long lifetime even when working on the upper limit of the cell.

The figure on the right provides a view into the orifice of a hot HTEZ-W cell. The red-hot filament is clearly visible.

The HTEZ-W design allows mounting ceramic crucibles (e.g. BeO) directly into the cell without outer metal crucible. In this way a higher temperature of the evaporation material in the crucible can be achieved.
HTEZ-W filament



Application

The HTEZ-W is designed for evaporation or sublimation of low vapor pressure elements and compounds at temperatures up to 2000°C, e.g. for materials like Fe, Cr, Ni, Co, V, Pt, Ti, La etc. Typical applications are surface science analysis or thin film deposition of magnetic or oxide layers.

The maximum operating temperature of the HTEZ-W may be limited by the crucible choice, e.g. to 1600°C with PBN. Furthermore, possible reactions of evaporants with the crucible material should be taken into account, which may also reduce the maximum advisable temperature.

Please refer to the Selection Guide for material data and decision-making advice.


Technical Data

Filament type free-standing tungsten filament
Thermocouple W5%Re/W26%Re (type C)
Operating temperature max. 2000°C, depending on crucible material 
Outgassing temperature max. 2000°C, depending on crucible material
Bakeout temperature 250°C
Cooling integrated water cooling
Crucibles 10 cm³; Al2O3, BeO, Ta, W crucibles (other materials on request)
Options


Crucibles

Standard crucible sizes is 10 cm³. Different crucible materials such as Al2O3, BeO, Ta, W, pyrolytic graphite (PG) and pyrolytic boron nitride (PBN) can be applied. For detailed information on crucibles see Crucibles.

Please specify crucible material upon ordering, or inquire for our recommendation.


HTEZ-W crucibles
Different ceramic and metal 10 cm³ crucibles for HTEZ-W


Dimensions

Schematic drawing HTEZ-W Schematic drawing of the High Temperature Effusion Cell HTEZ-W

(drawing shows
HTEZ-W 40-10-32)



Specific data

For general information on CF mounting flanges see Flange and Gasket dimensions.

[cm³] [mm] [mm] / [mm] [W] / [A] Product code Product code
HTEZ-W 40 - 10 - 32 - T - LxxxD36 920 / 34 PS 40-38 Ta 10-32
** no standard, please inquire for your particular solution
*** specify UHV length L with order


Product code:

e.g. HTEZ-W 40-10-32-T-L250D36

is a high temperature effusion cell on DN40CF-flange with 10 cm³ crucible (lip Ø 32 mm), Tantalum crucible, in-vacuum length 250 mm and diameter 36 mm.