Quartz-tube furnace

• NAME
• How to put the sample in.
• How to anneal the sample.
• How to get the sample out.
• Eurotherm settings

NAME

How to put the sample in.

1. Make sure that the quartz tube is on atmospheric pressure.
   
   
2. Release the clamp and take the tube from the vacuum system.
   
   
3. Insert the sample into the tube, mount the tube again, and make sure that the tip of thermocouple is right above the sample.

How to anneal the sample.

1. Slide the furnace around the quartz tube such that the sample is halfway the furnace.
   
   
2. Connect thermocouple and pen-plotter to the thermocouple socket at the backside of the controller/power supply. Connect the furnace to the socket marked 'oven'.
   
   
3. Turn on the water cooling of the diffusion pump.
   
   
4. Close the small leakage valve, turn on the rotation pump, and open valve V2 to the vacuum system.
   
   
5. Switch on the pressure meter and select TPR2.
   
   
6. Wait until the pressure is ~0.1 mbar before opening 'valve V1' to the diffusion pump.
   
   
7. Switch on the diffusion pump, open valve V3 on the diffusion pump, and close valve V2.
   
   
8. Fill the liquid N2 trap as soon as the diffusion pump works properly (p < 0.001 mbar).
   
   
9. Program the Eurotherm using the settings for either vacuum or hydrogen (see Eurotherm_settings).
   
   
10. Switch on the pen-plotter. Set the velocity to 120 cm/h and adjust the sensitivity according to the preset temperature. Note that the thermocouple output is ~0.04 mV/°C.
    
    
11. Wait until the pressure is ~10^-5 mbar. Then switch on the power supply of the furnace and start the heating process by pressing the button Run/Hold on the Eurotherm controller.

How to get the sample out.

1. Switch off the power supply of the furnace.
   
   
2. Switch off the diffusion pump and close valve V3.
   
   
3. Let the diffusion pump cool down (takes ~30 min).
   
   
4. Close valve V1 and valve V2.
   
   
5. Open the leakage valve sufficiently to let some air in, and then turn off the rotation pump. This order of handlings prevents any pump oil from entering the vacuum system.
   
   
6. Open the H2-gass valve and bring the quartz tube to atmospheric pressure, slide the furnace back, and dismount the quartz tube.

Eurotherm settings

    Sp(°C)  Pb      ti      td      cbl     cbh     Hl      Hc

     100   17.4    1130     off     off     off     25      5.0
     200   18.4     544     off     off     off     25      5.0
     300   13.1     635     off     off     off     50      5.0
     400    1.2     271     off     off     off    100     16.6
     500    1.1     179     off     off     off    100     12.8
     600    0.8     124     off     off     off    100      8.8
     800    2.5      82     off     off     off    100      6.8
    1000    4.3      75     off     off     off    100      6.2

    Sp(°C)  Pb      ti      td      cbl     cbh     Hl      Hc

     100    9.7     148     off     off     off     25     12.3