pizza talk 2006

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FIM/AFM/STM updateTill Hagedorn: 

FIM/AFM/STM update Till Hagedorn Pizza Talk Nov 15th, 2006

The people history…: 

The people history… Now: Mehdi, me and lots of help from Yoichi Past: Yan Sun, Anne-Sophie Lucier, Henrik Mortensen Past past: Graham Cross, Andre Schirmeisen FIM/AFM/STM chamber + microscope built by Adam Stadler (about 1993/94)

Reminder: what we do: 

Reminder: what we do

Tip image: FIM mode: 

Tip image: FIM mode He pressure: 10-5 mbar; HV = 3-4 kV

Measurement process: 

Measurement process

Challenge 1: Noise damping done by bungee cords: 

Challenge 1: Noise damping done by bungee cords Next: measurement of the noise transfer into the System (transfer function)

Tunneling gap instability: 

Tunneling gap instability

Challenge 2: Tunneling gap unstable: 

Challenge 2: Tunneling gap unstable Following SP I_t Deflection signal Z voltage good good bad bad

Challenge 2: Tunneling gap unstable: 

Challenge 2: Tunneling gap unstable Electrical + Mechanical contact Switching mode modulation No modulation

Challenge 2: Tunneling gap unstable: 

Challenge 2: Tunneling gap unstable Two consecutive scans STM of Au(111) on mica cantilever with PW cut tip

Electronic noise test with white noise input: 

Electronic noise test with white noise input Usual noise level on I_t signal: 60-80 mV input

Electronic noise from I_t: 

Electronic noise from I_t input

Solution 1 for tunneling gap: new coarse approach: 

Solution 1 for tunneling gap: new coarse approach OLD: screw mechanism New: moving hexagon

Solution 2: stabilization of STM cage by replacing front wall: 

Solution 2: stabilization of STM cage by replacing front wall