CoRuCo Trilayers with InPlane Anisotropy

MFM has proven to be an effective tool for detecting FM AF interlayer coupling and exploring magnetic domain structures in exchange-coupled layered thin films. Ultrathin Co Ru Co trilayers consisting of two Co layers of equal thickness (5 nm) with in-plane anisotropy, exchange-coupled through a nonmagnetic Ru spacer layer of variable thickness was studied by MFM 46 . The effect of the variable Ru interlayer thickness on the exchange coupling and thus the magnetic domain structure during the FM...

Ab Dc

Fig. 2.1 Feedback mechanisms for (a) Contact mode, the deflection is measured by the photodiode and kept constant by adjusting the z piezo. (b)Amplitude modulation, via the lock-in amplifier the amplitude and the phase response of the cantilever is measured and the amplitude is kept constant by adjusting the z piezo. (c) Frequency modulation, via the frequency demodulator the frequency shift is measured and kept constant by adjusting the z piezo Fig. 2.1 Feedback mechanisms for (a) Contact...

Cantilever Dynamics and Mechanical Bandwidth in TMAFM

In this section, we analyze the frequency response of an AFM probe when operated in TM-AFM and discuss the limitations imposed by the probe mechanical bandwidth on the measurements of tip-sample interaction forces. As mentioned before, in TM-AFM the tip interacts with the surface repeatedly at a rate close to the cantilever resonance frequency. Therefore, in steady state, the tip-sample interaction force waveform is treated as a periodic signal and can be expressed as a Fourier series. Fts(t) -...

Miles Fast Scanning AFM

Miles' group developed an ultra-high-speed AFM 31-33 . The most unique aspect of their AFM is in the scanner system, with the combination of a normal piezo scanner, flexure stage, and a special tuning fork scanner 34 as the x-scanner. In this system, the fast line scan (x-axis) was produced by a tuning fork oscillating at its resonance frequency of about 32 kHz and the slow line scan (y-axis) was produced by the flexure stage, which enables ultra high-speed scanning (1,300 fps). However, the...

Au on FeOPt111

The adsorption of Au on the FeO Pt(111) system was investigated with low temperature STM (5 K) and in a very low coverage regime we should remark that, in clear contrast to the described experiments so far, at this temperature the adsorbed metal diffusion coefficients are extremely low, and only Au adatoms or perhaps small aggregates are expected. However, these working conditions are useful to rule out the role of diffusion barriers in the NP growth. The FeO UT film shares some structural...

Info

Fig. 4.17 Composite image of four representative measured GISAXS scattering patterns (upper row) and corresponding simulations (lower row). The images were taken after deposition of gold layers with thicknesses of 2.5, 5.6, 8.8, and 15.1 nm. The elongated dark line in the middle of the measured images is the rod-like beam stop and the single spot the point-like beam stop to shield the specular beam. The evolving maxima in vertical direction originate from the growth in height, the lateral...

Detection Schemes

Bending of flexible cantilevers can be detected using various techniques, including the optical lever 46,47 , optical interferometers 48,49 , and piezoresistive sensors 50 . Due to its simplicity, the most popular is the optical lever, in which a collimated laser beam is reflected from the back of the cantilever to a four-quadrant photodiode. The position of the reflected laser spot on the photodiode changes due to flexural or torsional bending of the cantilever beam. Resulting vertical and...

1

Fig. 11.4 Geometries and methods used in X-STM I - breaking a scratched sample, II -cleaving a sample by pressing a wedge into a notch (from Ref. 40 ) consists of strain applied perpendicular to the facets and to the crack front, mode II consists of a shear force parallel to the facets and perpendicular to the crack front, whereas in mode III a shear force is applied parallel to the facets and to the crack front. Neglecting binding angles, only mode I will break bonds on the atomic scale....

Interferometric Grating Sensor

In the actual probe geometry (shown in Fig. 1.2), the large and small masses correspond to cantilever beam and the tip-coupled force sensor at the end, respectively. In order to measure the differential tip-cantilever displacement, an interferometric grating displacement sensor 38-40 is used. The grating sensor is designed such that the tip is mechanically coupled to alternating grating fingers, while the rest of the grating fingers are isolated from each other and remain free. Therefore, when...

NFMM Characterization of Magnetic Domains

Magnetic Domains Hard Disk

We demonstrate the measurement of electromagnetic properties of magnetic layers in a HD platter by using a NSMM. As the magnetization changed, the intensity of the reflection coefficient Sn varied. The electromagnetic properties of a hard disk were estimated by measuring the microwave reflection coefficient Sn. Figure 5.25A shows the estimated microwave reflection coefficient dependence on the magnetic relative permeability of the CoCrPtTa soft magnetic layer of the HD plater. The inset shows a...

Finite Element Model

Another, perhaps more natural observable in NFMM experiments, is the reflection coefficient Su as a function of frequency from which, of course, the frequency shift can be obtained or Sn as a function of material property for a fixed frequency 20,21 . However, to model Sn is not very straightforward in that one cannot work solely with electrostatics. Furthermore, there are distance scales of very different sizes, for example, the cavity of order centimeters and the tip-sample distance of order...

Near Field Microwave Microscopy for Nanoscience and Nanotechnology

Kiejin Lee, Harutyun Melikyan, Arsen Babajanyan, and Barry Friedman Abstract We have demonstrated the possibility of near-field microwave imaging of physical structures, such as thin films, bulk material, fluids, etc. by using a near-field microwave microscopy NFMM . We have developed theoretical models for the microwave reflection coefficient Sii and resonant frequency shift Af f0 dependence on electromagnetic characteristics, in particular, electrical conductivity, dielectric permittivity,...

Sarioglu Solgaard

Gerber, Atomic force microscope. Phys. Rev. Lett. 56, 930 1986 2. F.J. Giessibl, S. Hembacher, H. Bielefeldt, J. Mannhart, Subatomic features on the silicon 111 - 7 x 7 surface observed by atomic force microscopy. Science 289, 422 2000 3. N.A. Burnham, R. J. Colton, Measuring the nanomechanical properties and surface forces of materials using an atomic force microscope. J. Vac. Sci. Technol. A 7, 2906 1989 4. M. Radmacher, J.P. Cleveland, M. Fritz, H.G. Hansma, P.K....

Fabrication

Tip Etching Afm

The fabrication process is outlined in Fig. 1.13. The probes are fabricated in parallel using optical lithography. The fabrication process starts with a silicon-on-insulator SOI wafer Fig. 1.13a . First, the height offset between the reference and moving grating fingers to ensure maximum force sensitivity is created using Local Oxidation of Silicon LOCOS . In this process, an 80-nm-thick layer of stoichiometric silicon nitride film is deposited using low pressure chemical vapor deposition LPCVD...

Time Resolved Tapping Mode Atomic Force Microscopy

Ali Fatih Sarioglu and Olav Solgaard Abstract Atomic force microscopy has unprecedented potential for quantitative mapping of material-specific surface properties on the nanoscale. Unfortunately, methods developed for local stiffness measurements suffer from low operational speeds and they require large forces to be applied to the surface, limiting resolution and precluding measurements on soft materials such as polymers and biological samples. On the other hand, tapping-mode AFM, which is well...

Contents

Part I Scanning Probe Microscopy Techniques 1 Time-Resolved Tapping-Mode Atomic Force Ali Fatih Sarioglu and Olav Solgaard 1.2 Tip-Sample Interactions in 1.2.1 Interaction Forces in 1.2.2 Cantilever Dynamics and Mechanical Bandwidth in 1.3 AFM Probes with Integrated Interferometric High Bandwidth Force 1.3.1 Model 1.3.2 Interferometric Grating 1.3.3 Sensor Mechanical Response amp Temporal Resolution 19 1.3.5 Detection Schemes 1.3.6 Characterization and 1.3.7 Time-Resolved Force 1.4 Imaging...

Contributors

Stefano Agnoli Dipartimento di Scienze Chimiche e unit di ricerca, INSTM, Universit di Padova, Via Marzolo 1, 35131 Padova, Italy, stefano.agnoli unipd.it Johan Angenete Nanofactory Instruments, Sven Hultins gata 9A, 412 88 Gothenburg, Sweden, johan.angenete nanofactory.com Arsen Babajanyan Department of Physics and Basic Science Institute for Cell Damage Control, Sogang University, Seoul 121-742, Korea, barsen12 gmail.com Mirko Ballarini Department of Physics, Politecnico di Torino, 10129...