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1

Hard X-ray Microscopy with Elemental, Chemical and Structural Contrast

100%

Schroer C., Boye P., Feldkamp J., Patommel J., Schropp A., Samberg D., Stephan S., Burghammer M., Schöder S., Riekel C., Lengeler B., Falkenberg G., Wellenreuther G., Kuhlmann M., Frahm R., Lützenkirchen-Hecht D., Schroeder W.

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issue 2

357-368

EN

We review hard X-ray microscopy techniques with a focus on scanning microscopy with synchrotron radiation. Its strength compared to other microscopies is the large penetration depth of hard x rays in matter that allows one to investigate the interior of an object without destructive sample preparation. In combination with tomography, local information from inside of a specimen can be obtained, even from inside special non-ambient sample environments. Different X-ray analytical techniques can be used to produce contrast, such as X-ray absorption, fluorescence, and diffraction, to yield chemical, elemental, and structural information about the sample, respectively. This makes X-ray microscopy attractive to many fields of science, ranging from physics and chemistry to materials, geo-, and environmental science, biomedicine, and nanotechnology. Our scanning microscope based on nanofocusing refractive X-ray lenses has a routine spatial resolution of about 100 nm and supports the contrast mechanisms mentioned above. In combination with coherent X-ray diffraction imaging, the spatial resolution can be improved to the 10 nm range. The current state-of-the-art of this technique is illustrated by several examples, and future prospects of the technique are given.

2

AFM, XRD and HRTEM Studies οf Annealed FePd Thin Films

80%

Perzanowski M., Zabila Y., Morgiel J., Polit A., Krupiński M., Dobrowolska A., Marszałek M.

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issue 2

423-426

EN

Ferromagnetic FePd L 1_{0} ordered alloys are highly expected as forthcoming high-density recording materials, because they reveal a large perpendicular magnetocrystalline anisotropy [1]. The value of the magnetic anisotropy of FePd alloy strongly depends on the alloy composition, degree of alloy order as well as on the crystallographic grain orientation. In particular, to obtain the perpendicular anisotropy, it is necessary to get the films with (001) texture. One of the successful methods, which allows one to obtain highly ordered alloy, is a subsequent deposition of Fe and Pd layers, followed by an annealing at high temperature. This paper presents the study of the FePd thin alloy film structure changing in the result of high temperature annealing. During the annealing in high vacuum, the measurements of electrical resistance were performed, indicating the regions of different structure evolution. Changes in the crystal structure and surface morphology induced by thermal treatment were investigated by X-ray diffraction, atomic force microscopy, as well as high resolution transmission electron microscopy and then compared with electrical resistivity measurement. The slow thermal annealing of the deposited layers leads to the formation of L 1_{0} ordered FePd alloy with preferred (111) grain orientation. After the annealing at the highest used temperature, the dewetting process was observed, resulting in a creation of well oriented, regular nanoparticles.

3

Diffraction from WS_2 and MoS_2 Nanotubes

80%

Damnjanović M., Vuković T., Milošević I.

Acta Physica Polonica A

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2011

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vol. 120

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issue 2

224-226

EN

We present a symmetry based analysis of diffraction intensities of transition metal dichalcogenide nanotubes. Obtained results point out specific features of the intensity distribution that are related to group parameters. It is possible to read out all the group parameters from diffraction patterns, and therefore to characterize nanotube, since symmetry group uniquely determines the chiralty indices.

4

Scanning X-ray Microscopy with a Single Photon Counting 2D Detector

80%

Stachnik K., Meents A.

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vol. 125

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issue 4

902-906

EN

The experimental application of a novel technique utilizing a high resolution 2D pixel detector (PILATUS) in scanning transmission X-ray microscopy is presented. Measurements were performed at beamline P11 at the PETRA III synchrotron light source. Results are compared to the approach based on a segmented-type detector. A full simulation of the experimental line has been implemented in C++ programming language. Concepts of ptychography and its application in X-ray microscopy are also briefly discussed.

5

Electrical, Surface Morphology and Magneto-Capacitance Properties of Pb Free Multiferroic (BiFeO_{3})_{1-x}(BaTiO_{3})_{x} Solid Solutions

80%

Shariq M., Kaur D., Chandel V., Siddiqui M.

Acta Physica Polonica A

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2015

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vol. 127

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issue 6

1675-1680

EN

The solid solutions (BiFeO_{3})_{1-x}(BaTiO_{3})_{x} (x=0, 0.1, 0.2, 0.3, 0.4, and 0.5) have been synthesized adopting a solid state sintering route. Well crystalline phase of (BiFeO_{3})_{1-x}(BaTiO_{3})_{x} ceramics at different level of x has been optimized at sintering temperature of 950°C for 2 h. Dielectric, polarization and magnetocapacitance properties were investigated for different content level of BaTiO_{3}. Dielectric constant increased with increasing concentration of BaTiO_{3} up to x=0.3 for all the frequencies of 10, 100, and 1000 kHz. Dielectric loss in the material is attributed to space charges, interfacial and dipolar polarizations. Measurements of P-E loop indicated evident ferroelectricity in all samples. Well formed grain with varying grain sizes and nearly uniform shape was found for ceramics samples.

6

Contact Microscopy using a Compact Laser Produced Plasma Soft X-Ray Source

80%

Ayele M., Czwartos J., Adjei D., Wachulak P., Ahad I., Bartnik A., Wegrzynski Ł., Szczurek M., Jarocki R., Fiedorowicz H., Lekka M., Pogoda K., Gostek J.

Acta Physica Polonica A

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2016

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vol. 129

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issue 2

237-240

EN

Soft X-ray contact microscopy potentially allows imaging of wet living biological specimens at a spatial resolution higher than optical microscopy and without many of the constraints of scanning electron microscopy. In this paper, we present the development of a laboratory scale contact microscope that uses a laser produced plasma soft X-ray source. The source is based on a double-stream gas-puff target approach and it operates in the "water window" spectral range which enables to capture images of biological samples with a natural contrast. In the preliminary experiments the contact microscope system has been used for imaging of fixed and dried non-malignant HCV29 human bladder cell lines cultured on polymethyl methacrylate photoresists. The samples were exposed with 150 pulses of soft X-rays as an initial test to demonstrate the possibility of image formation. The soft X-ray contact images registered in the photoresists exhibit high resolution in the atomic force microscopy topography which indicates the potential application of soft X-ray contact microscopy in life science to examine small features as small as few tens of nm. The technique could also be used for living cell imaging with further optimization of the microscope system and development of a special specimen holder. The details of the soft X-ray contact microscopy technique and the experimental results are presented and discussed.

7

Zone-Plate Based Nanospectroscopy with Soft X-Rays at the SLS

80%

Fink R., Hub C., Tzvetkov G.

Acta Physica Polonica A

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2009

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vol. 115

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issue 2

462-466

EN

With the advance of nanostructuring techniques and the availability of third-generation synchrotron sources, Fresnel-type zone plate optics is widely used for nanospectroscopic investigations with resolutions of several 10 nm. Whereas hard X-rays commonly use diffraction or elemental contrast (e.g. using X-ray fluorescence), soft X-rays are favored to utilize the spectroscopic contrast in the near-edge region of the absorption edge. In particular, for soft materials, the relevant C-, N- and O 1s absorption edges show distinct resonances which allow fingerprint-type chemical identification, even in water surroundings. Few selected examples from modern material science will be discussed to demonstrate that the combination of X-ray absorption spectroscopy with high spatial resolution yields new insight into the nanoscale properties of these materials.

8

Solution Growth of Well-Aligned ZnO Nanorods on Sapphire Substrate

80%

Jia G., Hao B., Lu X., Wang X., Li Y., Yao J.

Acta Physica Polonica A

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2013

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vol. 124

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issue 1

74-77

EN

Vertically well-aligned ZnO nanorods arrays were synthesized on sapphire substrates by chemical bath deposition. Those sapphire substrates were seeded to control the density and orientation of ZnO nanorods using sol-gel method. Well-aligned and uniformly distributed ZnO nanorods in a large scale were obtained with strongly (002) preferential orientation. The structural properties were characterized by X-ray diffraction spectrometer and morphological characteristics were analyzed by scanning electron microscopy, respectively. The ZnO nanorods are obvious hexangular wurtzite structure and preferentially oriented along the c-axis (002) and growth vertically to the substrates. The optical properties were further thoroughly studied. What is more, the influences of the strain between substrate and ZnO nanorods due to thickness of the ZnO seed-layer on the characteristics and optical properties of ZnO were also analyzed.

9

FTIR Study of Multifunctional Coatings

70%

Paluszkiewicz C., Długoń E., Kwiatek W.

Acta Physica Polonica A

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2012

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vol. 121

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issue 2

551-554

EN

Nanoparticles of hydroxyapatite (HAp) or tricalcium phosphates (TCP) connected with fibrous phase create biomimetic system between the natural fibrous and ceramic materials building a bone. Chemical bonding between the implant and host tissue takes place through the phosphate layer, which is created on the bioactive implant surface when in contact with the body fluids environment. The Fourier transform infrared spectroscopy can yield microstructural information on the segment level complementary to the morphological information acquired from X-ray scattering as well as electron microscopy. The Fourier transform infrared method is applied to study thin films on different substrates. Moreover, the Fourier transform infrared microscope technique allows to obtain surface and cross-section maps in reflection and transmission modes. This leads to visualization of chemical imaging between substrates and films. In this work, the coatings with different addition of nanohydroxyapatite were deposited by electrodeposition method on titanium and Ti6Al4V alloys. Additionally, sublayers, such as TiO_2, were used to increase hydroxyapatite coating adhesion. The selection of suspension composition, depositing time and layer heat treatment conditions have the conclusive influence on the films parameters. All these experimental parameters were monitored during the sample preparation procedure. Changes in phase composition of biomaterials were determined by the Fourier transform infrared reflection technique based on focal plane array detection system. It has been found that results obtained by the Fourier transform infrared spectroscopy show the differences between the studied samples as well as that optimum time of HAp deposition was 90 s.

10

Superconducting Properties of Mo_2Re_3B_x-Mo_3Re_2B_x Eutectic

70%

Andrzejewski B., Guilmeau E., Kowalczyk A., Jurga W.

Acta Physica Polonica A

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2007

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vol. 111

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issue 5

727-735

EN

We synthesized, for the first time, superconducting eutectic composed of two new superconducting phases, namely of Mo_2Re_3B_x and of Mo_3Re_2B_x (where x≈1) and investigated its basic transport, magnetic, and microwave properties. The transition temperatures T_c were equal to 6.6 K and to 8.7 K for Mo_3Re_2B_x and Mo_2Re_3B_x compound, respectively. The phases present in the eutectic were identified by means of energy dispersion spectroscopy analyses. It was also shown that the two phases in the eutectic were separated by thin boron interface and formed regular network of the Josephson junctions which very effectively absorbed microwave energy.

11

Optical and Structural Properties of Bismuth Doped ZnO Thin Films by Sol-Gel Method: Urbach Rule as a Function of Crystal Defects

61%

Keskenler E., Aydın S., Turgut G., Doğan S.

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vol. 126

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issue 3

782-787

EN

Bismuth (Bi) doped zinc oxide (ZnO:Bi) thin films were prepared on glass substrates by sol-gel spin coating technique using homogeneous precursor solutions, and effects of Bi doping on the structural and optical properties of ZnO were investigated. The crystalline of ZnO films shifted from polycrystalline nature to amorphous nature with Bi doping. The plane stresses (σ) for hexagonal ZnO and ZnO:Bi crystals were calculated according to the biaxial strain model. The Urbach rule was studied as a function of non-thermal component to the disorder (defects in crystal structures) which is especially observed in the case of non-crystal semiconductors. The calculated Urbach energies and steepness parameters of undoped ZnO and ZnO:Bi films varied between 44.33 meV and 442.67 meV, and 58.3 × 10^{-2} and 5.8 × 10^{-2}, respectively. The Urbach energies of the films increased with an increase in the Bi doping concentration and a great difference was observed for 7.0 mol.% doping. The band gap values of the films exhibited a fluctuated behavior as a result of doping effect.

12

Applications of a Compact "Water Window" Source for Investigations of Nanostructures Using SXR Microscope

51%

Torrisi A., Wachulak P., Fahad Nawaz M., Bartnik A., Adjei D., Vondrová Š., Turňová J., Jančarek A., Fiedorowicz H.

Acta Physica Polonica A

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2016

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vol. 129

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issue 2

169-171

EN

A compact soft X-ray microscope based on a nitrogen double-stream gas puff target soft X-ray source, operating at He-like nitrogen spectral line at the wavelength of λ =2.88 nm is presented. The desk-top size microscope was successfully demonstrated in transmission mode using the Fresnel zone-plate objective and it is suitable for soft X-ray source microscopy in the "water window" spectral range (λ = 2.3÷ 4.4 nm). Details about the soft X-ray source source, the microscope and an example of application in the biomedical field are shown and discussed.

Refine search results

Hard X-ray Microscopy with Elemental, Chemical and Structural Contrast

AFM, XRD and HRTEM Studies οf Annealed FePd Thin Films

Diffraction from WS_2 and MoS_2 Nanotubes

Scanning X-ray Microscopy with a Single Photon Counting 2D Detector

Electrical, Surface Morphology and Magneto-Capacitance Properties of Pb Free Multiferroic (BiFeO_{3})_{1-x}(BaTiO_{3})_{x} Solid Solutions

Contact Microscopy using a Compact Laser Produced Plasma Soft X-Ray Source

Zone-Plate Based Nanospectroscopy with Soft X-Rays at the SLS

Solution Growth of Well-Aligned ZnO Nanorods on Sapphire Substrate

FTIR Study of Multifunctional Coatings

Superconducting Properties of Mo_2Re_3B_x-Mo_3Re_2B_x Eutectic

Optical and Structural Properties of Bismuth Doped ZnO Thin Films by Sol-Gel Method: Urbach Rule as a Function of Crystal Defects

Applications of a Compact "Water Window" Source for Investigations of Nanostructures Using SXR Microscope