Determination of tip transfer function for quantitative MFM using frequency domain filtering and least squares method

Magnetic force microscopy has unsurpassed capabilities in analysis of nanoscale and microscale magnetic samples and devices. Similar to other Scanning Probe Microscopy techniques, quantitative analysis remains a challenge. Despite large theoretical and practical progress in this area, present methods are seldom used due to their complexity and lack of systematic understanding of related uncertainties and recommended best practice. Use of the Tip Transfer Function (TTF) is a key concept in making Magnetic Force Microscopy measurements quantitative. We present a numerical study of several aspects of TTF reconstruction using multilayer samples with perpendicular magnetisation. We address the choice of numerical approach, impact of non-periodicity and windowing, suitable conventions for data normalisation and units, criteria for choice of regularisation parameter and experimental effects observed in real measurements. We present a simple regularisation parameter selection method based on TTF width and verify this approach via numerical experiments. Examples of TTF estimation are shown on both 2D and 3D experimental datasets. We give recommendations on best practices for robust TTF estimation, including the choice of windowing function, measurement strategy and dealing with experimental error sources. A method for synthetic MFM data generation, suitable for large scale numerical experiments is also presented

Influences of Different Milk Yields of Holstein Cows on Milk Quality Indicators in the Czech Republic

The milk yield (MY) is an important economic and health factor closely connected with the health status of dairy cows, their reproduction performance, longevity and milk composition and properties (MIs). The differences within MIs between high yielding herd (Group 1; 10 282 kg per lactation) and three herds with average MY (Group 2; 7 926 kg) were tested. The files with 96 and 290 milk samples were collected in summer and winter feeding seasons and well balanced in lactation factors. Group 1 had higher genetical value, better nutrition and was milked three times per day and its MY was higher by 30% (P P P > 0.05). The U was probably higher due to higher loading of the nitrogen nutrition (4.27 > 3.57 mmol l-1) in MY 1. Surprisingly, SCC was higher (112 > 81 103 ml-1) and AC lower ((0.0374) 0.0250 -1) in Group 1. Both the MIs did not indicate problems of the health status. An indicator of energy nutrition balance as fat/protein ratio was not influenced (1.15 ± 0.24 versus 1.16 ± 0.23; P > 0.05), despite the large difference between MY 1 and 2. URN was higher in MY 1 (46.5 > 39.1%) due to more efficient nutrition, like in U. The high MY had no negative impacts on MIs with well balanced nutrition of Holstein cattle

Synthesis of carbon nanotubes in mw plasma torch with different methods of catalyst layer preparation and their applications

The microwave plasma torch (2 45 GHz) was used for the synthesis of carbon nanotubes from the mixture of CH4/H-2/Ar or C2H2/H-2/Ar on different substrates with iron catalyst Iron catalyst was prepared by vacuum evaporation of iron on Si, Si/SiOx or Si/AlxO(Y) substrates or by deposition of iron oxide nanoparticles on Si/SiOx substrate by decomposion of Fe(CO)(5) in gas feed Such prepared substrates were used for growth of carbon nanotubes. Recostruction of the iron catalyst layer into nanoparticles was also studied in dependence on substrate buffer layer, gas atmosphere and temperature Samples were studied by scanning and transmission electron microscopy and Raman spectroscopy. Synthesis resulted in rapid growth of MWNTs on all samples but the density, purity and nanotube diameter distribution varied Such prepared carbon nanotube layers were used for sensing applications

Depozice organosilikonových tenkých vrstev pomocí PECVD

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Depozice organosilanových polymerních vrstev plazmově připravených podpořených CVD

Deposition of Organosilicon Polymer Thin Films by Plasma Enhanced Chemical Vapor Deposition

Důležitost vlivu nukleační fáze na vlastnosti nanokrystalických diamantových vrstev připraveným metodou PECVD

Microcrystalline diamond finds several applications due to its high hardness but also as electronic and optical devices. However, its roughness makes some applications like tribology, emission cathodes for flat panel displays, optical coatings and emerging Nano/Micro-Electro-Mechanical Systems (N/MEMS) difficult. A major advance was achieved in early 90ties when the crystalline size was decreased from down to nanometers. However, the processes leading to the deposition of small grain-sized diamond films are not yet properly understood and these films exhibit different properties and morphology depending on the method of preparation. Therefore, the nanocrystalline diamond (NCD) covers very different materials such as columnary grown films with the grain sizes usually quoted below 100 nm (but 30 nm are nowadays possible)and continuous dense coatings with grain sizes reaching 5-15 nm grown under high re-nucleation rates

Uhlíkové nanostruktury pěstované v mikrovlnném a radiofrekvenčním výboji

The structural variety of carbon-based materials and high potential of plasma enhanced chemical vapor deposition method(PECVD)utilizing either radio frequency(r.f.)or microwave discharges is demonstrated in the present paper