Coarse tip distance adjustment and positioner for a scanning tunneling microscope

Frohn, J.; Wolf, J. F.; Besocke, K.; Teske, Michael P.

doi:10.1063/1.1140287

Cited by 202 publications

(67 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Accordingly, the temperature of the STM and sample are at 4.9 K, close to that of liquid He. The coarse tip approach is achieved with the inertial rotation 24 of a Mo disk residing on three ruby balls glued to three piezo feet (O " ϭ6.65 mm) pointing to the top. The Mo disk provides helical ramps with a height difference of 0.5 mm.…”

Section: Methodsmentioning

confidence: 99%

Thermal damping of quantum interference patterns of surface-state electrons

et al. 1999

View full text Add to dashboard Cite

The temperature-dependent damping of quantum-mechanical interference patterns from surface-state electrons scattering off steps on Ag͑111͒ and Cu͑111͒ has been studied using scanning tunneling microscopy ͑STM͒ and spectroscopy in the temperature range 3.5-178 K. The thermal damping of the electron standing waves is described quantitatively within a simple plane-wave model accounting for thermal broadening due to the broadening of the Fermi-Dirac distributions of sample and tip, for beating effects between electrons with different k ͉͉ vectors, and for inelastic collisions of the electrons, e.g., with phonons. Our measurements reveal that Fermi-Dirac broadening fully explains the observed damping for Ag and Cu. From the analysis of our data, lower limits of the phase-relaxation lengths at the Fermi energy E F of the two-dimensional electron gas of L (E F )տ600 Å at 3.5 K and տ250 Å at 77 K for Ag͑111͒, and of L (E F )տ660 Å at 77 K and տ160 Å at 178 K for Cu͑111͒ are deduced. In contrast to integral measurements such as photoemission we measure L close to E F and also locally. The latter eliminates residual line widths due to surface defect scattering found in the integrating techniques. Our STM results, therefore, currently provide a very good absolute estimate of L and the inelastic lifetime ϭL /v F , respectively. Our values can be combined with photoemission results on dL /dT to derive the inelastic lifetime of surface state electrons at any T. ͓S0163-1829͑99͒02524-2͔

show abstract

Section: Methodsmentioning

confidence: 99%

Thermal damping of quantum interference patterns of surface-state electrons

et al. 1999

View full text Add to dashboard Cite

show abstract

“…In this paper we report on further experimental and theoretical evidence for the vacancy mass transport mechanism. The evidence is based on a comparison of the activation energy for the decay rate of islands on Cu͑100͒ to results of firstprinciples calculations of the energy of vacancy formation and diffusion.The scanning tunneling microscope ͑STM͒ is based on the Besocke design, 13 and is capable of variable-temperature operation in the range of 50-500 K. The UHV chamber is equipped with an electron-beam evaporator for copper deposition. Special care was taken to degas the evaporator and the Cu source so that during deposition the pressure in the chamber never exceeded 1ϫ10 Ϫ10 mbar.…”

mentioning

confidence: 99%

“…The scanning tunneling microscope ͑STM͒ is based on the Besocke design, 13 and is capable of variable-temperature operation in the range of 50-500 K. The UHV chamber is equipped with an electron-beam evaporator for copper deposition. Special care was taken to degas the evaporator and the Cu source so that during deposition the pressure in the chamber never exceeded 1ϫ10 Ϫ10 mbar.…”

mentioning

confidence: 99%

Activation energy for the decay of two-dimensional islands on Cu(100)

et al. 1998

View full text Add to dashboard Cite

Experimental data on the decay rate of two-dimensional islands on Cu͑100͒ as a function of temperature are reported. The decay is limited by the attachment-detachment process. A comparison of the experimentally observed activation energy for the decay rate with results from first-principles theory renders further support to the understanding that on Cu͑100͒ island decay is due to mass transport via vacancies. ͓S0163-1829͑98͒50836-3͔The coarsening of two-dimensional ͑2D͒ islands on surfaces has been studied quite extensively in the past. On metal surfaces, different mechanisms for the coarsening process have been found to be operative. One is the classical mechanism of Ostwald ripening 1 in which islands of larger size gain atoms at the expense of smaller ones. The thermodynamic driving force for the ripening process is the larger chemical potential of smaller islands. Akin to Ostwald ripening is the decay of islands in the vicinity of steps in which islands lose atoms to the ascending step edges. On metal surfaces where steps are abundant even on well-prepared surfaces, this process of island decay effectively competes with the Ostwald ripening, in particular at later times in the coarsening process. Another important coarsening mechanism is a consequence of the surprisingly large mobility of islands, vacancy islands, and steps on surfaces. [2][3][4][5][6][7] Because of the high mobility, the small islands generated by homogeneous nucleation engage in a random walk on surfaces, meet occasionally, and coalesce. For the Cu͑100͒ and the Ag͑100͒ surface this random-walk-induced coalescence can be the prevailing mechanism in the coarsening process. [8][9][10] Until recently it was tacitly assumed that atom exchange between islands and steps on metal surfaces is mediated via adatoms on the terraces as the diffusing species. In a recent study of Ostwald ripening on Cu͑100͒ it was proposed that single atom vacancies rather than adatoms are responsible for the mass transport between the islands. 11 The argument was based on the time dependence of the island decay that called for an activation energy for the attachment of the diffusing species to an island. As it is rather difficult to envision an activation barrier for the attachment of adatoms to an ascending step on a metal surface but quite natural to assume a barrier for the attachment of vacancies, vacancies were proposed to be the prevailing mass transport carrying species on Cu͑100͒. A recent theoretical study 12 has indeed shown that the activation energy for diffusion of vacancies on Cu͑100͒ is smaller than for adatoms, rendering further support for the model of vacancy mediated coarsening on this surface. In this paper we report on further experimental and theoretical evidence for the vacancy mass transport mechanism. The evidence is based on a comparison of the activation energy for the decay rate of islands on Cu͑100͒ to results of firstprinciples calculations of the energy of vacancy formation and diffusion.The scanning tunneling microscope ͑STM͒ is based on...

show abstract

“…Begin with a cryogenic-capable scanning probe microscope with associated control electronics. The microscopes used for the research described here use inertial translation to "walk" the sample towards and away from the tip along ramps 13 (made from a conducting material such as copper, brass, or stainless steel to enable them to transmit bias voltage to the sample) as part of a Besocke design STM 14 , schematically shown in Figure 2. 2.…”

Section: Protocolmentioning

confidence: 99%

Scanning-probe Single-electron Capacitance Spectroscopy

Walsh

Romanowich

Gasseller

et al. 2013

JoVE

View full text Add to dashboard Cite

The integration of low-temperature scanning-probe techniques and single-electron capacitance spectroscopy represents a powerful tool to study the electronic quantum structure of small systems -including individual atomic dopants in semiconductors. Here we present a capacitance-based method, known as Subsurface Charge Accumulation (SCA) imaging, which is capable of resolving single-electron charging while achieving sufficient spatial resolution to image individual atomic dopants. The use of a capacitance technique enables observation of subsurface features, such as dopants buried many nanometers beneath the surface of a semiconductor material 1,2,3 . In principle, this technique can be applied to any system to resolve electron motion below an insulating surface.As in other electric-field-sensitive scanned-probe techniques 4 , the lateral spatial resolution of the measurement depends in part on the radius of curvature of the probe tip. Using tips with a small radius of curvature can enable spatial resolution of a few tens of nanometers. This fine spatial resolution allows investigations of small numbers (down to one) of subsurface dopants 1,2 . The charge resolution depends greatly on the sensitivity of the charge detection circuitry; using high electron mobility transistors (HEMT) in such circuits at cryogenic temperatures enables a sensitivity of approximately 0.01 electrons/Hz ½ at 0.3 K 5. Video LinkThe video component of this article can be found at

show abstract

Coarse tip distance adjustment and positioner for a scanning tunneling microscope

Cited by 202 publications

References 1 publication

Thermal damping of quantum interference patterns of surface-state electrons

Thermal damping of quantum interference patterns of surface-state electrons

Activation energy for the decay of two-dimensional islands on Cu(100)

Scanning-probe Single-electron Capacitance Spectroscopy

Contact Info

Product

Resources

About