ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
A new and stable scanning tunneling microscope (STM) system has been constructed for the investigation of thin organic films in air. The STM unit is made of Macor, which is machinable ceramic and has a small thermal expansion coefficient and a high mechanical stiffness. Three-dimensional coarse position adjustment (within 3 μm) is carried out using five stacked piezoelectric transducers (PZTs). A cross-type configuration is used to prevent the thermal effect of the x- and y-direction displacement mechanism. In order to achieve high resolution, x-, y-, and z-direction displacements are performed using a tube-type PZT. The z direction of the tube PZT has a high mechanical resonant frequency of 24.4 kHz. Therefore, this STM unit is mechanically rigid, and allows stable operation under mechanical disturbances (sound and mechanical vibration). Moreover, this STM unit can be controlled for 24 h or longer by using an ordinary operational amplifier, because thermal effects are compensated. The STM system can also be used to obtain information on the spatially resolved local tunneling barrier height, which is sensitive to the chemical structure of the sample. The capabilities of this newly designed STM are demonstrated with experiments investigating the morphology and tunneling barrier height of stearic acid thin films on indium-tin-oxide substrates. © 1997 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1147892
