Transfer of chirality
Feb/17 Paper published in Nature Chemistry including News&Views. »more info

Towards chemical recognition of molecules
Aug/16 Paper published in ACS Nano. »more info

Odehnal award
June/16 O. Stetsovych received Odehnal award »more info

Praemium Academiae
June/16 P. Jelinek received CAS award »more info

Imaging electrostatic field
May/16 paper in Nature Comm. »more info

O. Wichterle prize
May/16 P. Hapala received O. Wichterle prize for outstanding young scientists at the AS CR. »more info

On-surface chemical synthesis
Apr/16 paper in JACS »more info

Structural and Electronic Properties of Nitrogen-Doped Graphene
Mar/16 Paper in Phys. Rev. Lett. »more info

Role of the electrostatic force in AFM images
Mar/16 Paper in Phys. Rev. Lett »more info

Charge transport between two molecules
Sep/15 Paper in Phys. Rev. Lett »more info

The best poster ECOSS-31
Sep/15 Our work has been selected as the best poster in the ECOSS-31 conference. »more info

Paper in ACS Nano
Aug/15 Novel way of B,N-co doping of graphene demonstrated. »more info

paper in PRL and Physics
Aug/15 Our work has been published in Phys. Rev. Lett highlighted as Synopsis in Physics. »more info

Paper in Nature Comm.
Jul/15 High-resolution AFM images reported at room temperature. »more info

Paper in Nano Letters
Jun/15 The current and the force used for controlled atomic switching of silicon tetramer. »more info

O. Wichterle prize
May/15 M. Ondracek received O. Wichterle prize for outstanding young scientists at the AS CR. »more info

Simultaneous nc-AFM/STM measurements using Qplus sensor

We performed simultaneous Scanning Tunneling and frequency modulated dynamic Atomic Force Microscopy measurements with a qPlus setup. The qPlus sensor is a purely electrical sensor based on a quartz tuning fork. If both, the tunneling current and the force signal will be measured at the tip, a cross-talk of the tunneling current into the force signal can easily occur. We investigated origin and general features of the capacitive cross-talk in detail. Furthermore, we modified an experimental setup which improves the level of decoupling between the tunneling current and the deflection signal. The efficiency of this experimental setup was demonstrated on the topography and site-specific force/tunneling spectroscopy measurements on the Si(111)-7x7 surface. The results show an excellent agreement with previously reported data measured by optical interferometric deflection.

Z. Majzik, M. Setvín, A. Bettac, A. Feltz, V. Cháb, P. Jelínek Simultaneous current, force and dissipation measurements on the Si(111) 7×7 surface with an optimized qPlus AFM/STM technique Beilstein J. Nanotechnol. 3, 249 (2012).

In addition we performed a detail comparison of three different methods that can be used for estimating the stiffness of qPlus sensors. The first method was based on continuum theory of elasticity. The second (Cleveland's method) used the change in the eigenfrequency, which is induced by loading of small masses. Finally, the stiffness was obtained by analyses of the thermal noise spectrum. We show that all three methods give very similar results. Surprisingly, neither the gold wire nor the gluing rises to significant changes of the stiffness in the case of our homebuilt sensors.
Furthermore we described a fast and cost-effective way to perform the Cleveland's method. This method is based on gluing small pieces of a tungsten wire, the mass was obtained from the volume of the wire (see Fig. bellow), which is measured by optical microscope. To facilitate detection of oscillation eigenfrequencies under ambient conditions, we designed and built a device for testing qPlus sensors.

J. Berger, M. Švec, M. Muller, M. Ledinský, A. Fejfar, P. Jelínek and Zsolt Majzik
Characterization of the mechanical properties of qPlus sensors Beilstein J. Nanotechnol. 4, 1–9 (2013)