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EDG Furnace

The EDG is the flagship of MELLEN's furnaces.  The Electro-Dynamic Gradient Furnace or EDG has numerous advantages and models making for ultimate conditions for all applications.

The EDG makes it possible to create a flat zone area inside the furnace called an isothermal zone.  The isothermal zone is one in which all zones measure the same temperature, creating an ideal environment for many applications.  The controlled temperatures range from 100^oC to 1600^oC and anywhere in between.

The EDG allows the operator the ability to establish a gradient or length of controlled temperature between zones where the temperature varies a pre determined amount.  Consider the possibilities of having a temperature spike or a gradual increase/decrease in temperature throughout the furnace.  For more information about a flat spike, click here.

The EDG allows the user uniform temperature control.  With the EDG's numerous zones and power supply, (a standard EDG uses 24 zones) a user can set and maintain a temperature.  This constant setting allows for reliability and repeatability within your lab.

The MELLEN designed ADAPT System is designed specifically for use with the EDG, a s a computer based control mechanism.  The ADAPT system offers many user friendly features, such as programming control, security features, graphing and PIV tuning.

EDG Crystal Growth Furnace 

The MELLEN Gradient Freeze Method minimizes thermal stress and eliminates mechanical stress due to motion and vibration.  Best describe as a combination between the Bridgman and Linear Gradient Freeze Technique, the MELLEN Gradient Freeze Method differs from the standard gradient freeze in five ways:

• The span, the slope and the maximum temperature of the work is controlled over the full length of the work with precision and repeatability.

• A flat zone across the ingot is established before, during and after the gradient passage.

• Computer Controlled linear movement of the interface

• No moving parts, no extraneous thermal currents

• Utilizes quadrant tuning (localized or total)

The MELLEN Method may be used both horizontally and vertically.  It is set up in similar fashion to the Bridgman profile approach.

Instead of moving the furnace or the work charge through the gradient, the gradient is backed up over the seed for "meltback" and then electronically moved forward over the melt.  This results in solidification of a work charge.

This process allows for the solid crystal material to remain in its own isothermal zone.  At the same time, the low temperature region that generates the atmosphere in the ampoule, is undisturbed.

Typical magnitudes of the gradient that can easily be handled by this method are:

 The EDG is a precision tool for research as well as production.

Also, the EDG has the optional feature of a Sight Glass, designed for distortion free viewing of the interior of the furnace.

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MELLEN can raise your temperature in more ways than one, the hotter the better.