Wyniki wyszukiwania - Biblioteka Nauki

1

Processing and Characterization of Fe-Cu-Ni Sinters Prepared by Ball Milling and Hot Pressing

100%

Borowiecka-Jamrozek J.

Archives of Metallurgy and Materials

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2020

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tom Vol. 65, iss. 3

1157--1161

EN

The main objective of the present work was to determine the effect of powder composition on microstructure and properties of iron-base materials used as matrices in diamond impregnated tools. The Fe-Cu-Ni powders premixed and ball-milled for 30 hours, were used for the experiments. The influence of manufacturing process parameters on microstructure and mechanical properties of produced sinters was investigated. Sintering was done by hot-pressing technique in graphite mould. The powders were consolidated to a virtually pore-free condition during 3 minutes hold at 35 MPa and 900°C. Investigations of the sintered materials included: density, hardness, static tensile test and X-ray diffraction (XRD) analysis. Microstructural and fractographic observations were also made with a scanning electron microscope (SEM). The obtained results indicate that the sintered parts have a high density, close to the theoretical value, good plasticity, relatively high hardness and yield strength, and are characterized by a coarse-grained microstructure.

2

Electron paramagnetic resonance and scanning electron microscopy characterization of diamond films fabricated by HF CVD method

100%

Fabisiak K. , Szreiber M. , Uniszkiewicz C. , Runka T. , Kasprowicz D.

Optica Applicata

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2009

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tom Vol. 39, nr 4

833-837

EN

Defects in diamond films, produced by the hot filament chemical vapour deposition (HF CVD) of methanol and hydrogen mixture as function of gas composition, were investigated by electron paramagnetic resonance (EPR), scanning electron microscopy (SEM) and Raman spectroscopy measurements. We found an isotropic g-value (2.003š0.0002) independent of growth conditions. The peak-to-peak of EPR line width changes from 0.3 to 0.6 mT and the spin density increases from 2.3ź1017 to 3.2ź1018 spin/cm-3 with increasing concentration of methanol vapour. The EPR line in general shows double character and was found to be superposition of two components, a narrower Lorentzian and a broader Gaussian, suggesting the existence of two different types of defects in diamond layer. EPR measurements were supported by SEM observation.

3

Węgiel w ureilitach

100%

Jakubowski T. , Karczemska A. , Kozanecki M. , Szurgot M. , Jakubowski K. , Mitura S.

Acta Societatis Metheoriticae Polonorum

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2011

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tom 2

184

4

Diamond side resonances: influence of isotopic substitution of carbon

100%

Ivanov A. A. , Ivanov A. I.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2017

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tom Vol. 21, No 2

173--176

EN

We discuss the side resonances of the optically detected magnetic resonance in a diamond crystal and propose a new approach to the calculation of the hyperfine interaction in a composed system consisting of a negatively charged nitrogen-vacancy NV- center and a nearby 13C nuclear spin. The energy levels, rule selection and radiative transitions are obtained by a new method. The base of this method is the use of a complete set of commuting operators and entangled spin states. An estimation of the carbon hyperfine splitting parameters in the diamond NV- center from side-resonance frequencies is obtained in the frame of this method.

5

Prostownicze właściwości struktur wykorzystujących odkształcony diament CVD

100%

Kulesza S. , Rozpłoch F. , Bała W.

Karbo

|

2000

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tom Nr 4-5

120-122

PL

Przedstawiono wyniki badań nad otrzymywaniem cienkich warstw diamentowych, wykazujących właściwości prostownicze. Na podstawie badań za pomocą skaningowej mikroskopii elektronowej (SEM) oraz widm Ramana określono morfologie warstw, udział poszczególnych faz wójtowych oraz rodzaj i wielkość naprężeń występujących w tych strukturach.

EN

The article presents the results of investigations on obtaining of diamond films showing rectifying properties. On the basis of the investigations done by scanning electronic microscopy (SEM) and Raman spectra the morphology of layers has been determined, share of particular carbon phases and kind and magnitude of stresses occurring in the structures.

6

A method and new parameters for assessing the active surface topography of diamond abrasive films

100%

Kacalak W. , Tandecka K. , Mathia T. G.

Journal of Machine Engineering

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2016

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tom Vol. 16, No. 4

95--108

EN

This paper describes the methodology and results of research on the tribological characteristics of the surfaces of diamond abrasive films using a stereometric analysis. Abrasive films are used in various finishing processes of surfaces with very high smoothness and accuracy. A morphological analysis of surface vertexes in the plane that is parallel to the film surface and the perpendicular direction allowed an assessment of the distances between particles by means of a decomposition of the surface into Voronoi cells. When studying the formation of the aggregates of diamond particles and the spaces between them, one may infer about the machining potential of the abrasive film and determine the recommended kinematic conditions of the film that ensures the maximum use of this potential. Owing to the investigations related to the morphology of diamond abrasive films, one can observe relevant characteristic abrasive aggregates that vary in term of size and shape depending on particle sizes. Units with elongated shapes have a superior machining ability in relation to spherical-shaped units. One of significant parameters proposed that describe the technological potential of abrasive films is the edge length to width ratio of diamond units. Different operating modes are discussed. A statistical analysis of the dynamics observed of abrasive interfaces allowed a pertinent description of the abrasive process taking into consideration nominal and apparent as well as abrasively efficient morphologies.

7

Structure and Properties of Ni/Diamond Nanocrystalline Coatings

100%

Mazurek A. , Trzaska M.

Archives of Metallurgy and Materials

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2019

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tom Vol. 64, iss. 4

1309--1314

EN

This paper presents the results of research of Ni/diamond composite coatings produced by electrochemical reduction method. Research was focused on composite coatings with nickel matrix and diamond as a disperse phase and for comparison purposes on nanocrystalline nickel coatings. Ni/diamond composite coatings were produced in baths with different content of nanodiamond powder. The structures of the dispersed phase and the composite coatings were analysed by using X-ray diffraction, scanning electron microscopy and light microscopy. Measurements of selected properties of the coatings were performed, including roughness, microhardness, adhesion and abrasive wear resistance. The research results indicate that the produced coatings have a compact structure and good adherence to steel substrate. Moreover, nanocrystalline Ni/diamond composite coatings exhibit greater hardness and reduced abrasive wear resistance compared to nanocrystalline nickel coatings.

8

Study of diamond film nucleation by ultrasonic seeding in different solutions

88%

Varga M. , Ižák T. , Kromka A. , Veselý M. , Hruška K. , Michalka M.

Open Physics

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2012

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tom 10

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nr 1

218-224

EN

In this study we have investigated diamond nucleation on Si substrates by ultrasonic seeding with different liquid solutions of Ultradispersed Detonation Diamond (UDD) powder in a mixture of metal nano- or microparticles (Ni, Co, Y). The influence of different solutions on nucleation efficiency was investigated. For highlighting nucleation centers and better evaluation of the nucleation process the nucleated samples were moved into a Microwave Plasma Enhanced Chemical Vapor Deposition (MW CVD) reactor and a ”short-time” (10 min), then followed by a ”long-time” (+1 hour), diamond deposition was performed. The morphology of samples was characterized by Scanning Electron Microscopy (SEM) and the chemical composition of grown diamond layer was investigated by Raman Spectroscopy. From the measurements we found out that microsized metal particles positively influenced nucleation and the uniformity of the deposited diamond thin film. The lowest surface roughness was achieved in the case of nanodiamond powder mixed with Co and Y metal powder. The influence of Ni, Co and Y to the nucleation and early growth stage are discussed.

9

Laser reflectance interferometry system with a 405 nm laser diode for in situ measurements of CVD diamond thickness

88%

Kraszewski M. , Bogdanowicz R.

Metrology and Measurement Systems

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2013

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tom Vol. 20, nr 4

543--554

EN

In situ monitoring of the thickness of thin diamond films during technological processes is important because it allows better control of deposition time and deeper understanding of deposition kinetics. One of the widely used techniques is laser reflectance interferometry (LRI) which enables non-contact measurement during CVD deposition. The authors have built a novel LRI system with a 405 nm laser diode which achieves better resolution compared to the systems based on He-Ne lasers, as reported so far. The system was used for in situ monitoring of thin, microcrystalline diamond films deposited on silicon substrate in PA-CVD processes. The thickness of each film was measured by stylus profilometry and spectral reflectance analysis as a reference. The system setup and interferometric signal processing are also presented for evaluating the system parameters, i.e. measurement uncertainty, resolution and the range of measurable film thickness.

10

Basics of the superfinishing results prognostication by the diamond lapping films

88%

Kacalak W. , Tandecka K.

Journal of Machine Engineering

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2012

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tom Vol. 12, No. 4

49--62

EN

Superfinishing with the use of diamond lapping films differs to a significant extent from other machining methods. This is finishing surface machining, one which is realized by a slow rewinding of a microfinishing film, putting it in an oscillating motion and pressing the tool to the surface being machined. The surface being machined moves with a speed which is substantially greater than that of the tool feed. A characteristic feature of the process is a one-time use of the tool, the result being a need of an optimal selection of the machining parameters. Investigations of the topography of the microfinishing film surface were conducted with the use of new parameters that describe the arrangement and the shape of the vertices of active grains. The following were used for the purpose of assessment: coefficients that had been developed that describe the features of the shape of the tool surface, such as the standardized coefficient of the flatness of vertices wNki, the standardized number of vertices in relation to an area unit LNwi and the dissipation coefficient of the height of the location of vertices wNrwi. For the purpose of the assessment of the smoothening ability of diamond lapping films the smoothening potential coefficient wp was developed, which is defined as the geometric mean of the abovementioned indices.

11

Fabrication and electrochemical properties of diamond layers grown on tungsten wire by HF CVD method

88%

Torz-Piotrowska R. , Uniszkiewicz C. , Szreiber M. , Wrzyszczynski A. , Staryga E. , Runka T. , Kasprowicz D.

Optica Applicata

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2009

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tom Vol. 39, nr 4

951-957

EN

Un-doped polycrystalline diamond thin films have been grown on tungsten substrates by hot filament chemical vapor deposition (HF CVD) using a hydrogen and methanol vapor mixture. Diamond films have been analyzed by Raman spectroscopy and scanning electron microscopy (SEM). Cyclic voltammetric behavior of diamond films of different quality and morphology has been studied in acetonitryle with (n-Bu)4NClO4 and in 0.1 M KCl aqueous solutions. Preliminary cyclic voltammetry (CV) measurements showed that our electrodes have a wide potential range over which negligible background response current is observed. The potential windows depend on the type of solvent. In the case of water solution the decomposition of water occurs electrochemically and evolves O2 during positive (anodic) polarization and H2evolution during negative (cathodic) polarization. The electrochemical properties of diamond electrodes have been evaluated by performing cyclic voltammetry measurements in [Fe(CN)6]3-/4- with 0.1 M KCl. The electrode demonstrates reversible kinetics during electrochemical analysis.

12

Uwzględnianie strefy odziaływania wiazki laserowej w obróbce diamentu

88%

Wyszyński D.

Inżynieria Maszyn

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2007

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tom R. 12, z. 4

87-93

PL

Obróbka laserowa staje się coraz bardziej atrakcyjną spośród metod obróbki diamentów. Zastosowanie źródeł laserowych o dużej energii impulsu, takich jak pompowany lampą laser Nd:YAG czy pompowany modułem diodowym laser Nd:YAG z konwersją długości fali, pozwala na wysoką wydajność wraz z doskonałą jakością krawędzi i powierzchni obrabianych materiałów w odniesieniu do poniesionych kosztów. Artykuł przedstawia wyniki wstępnych badań nad zastosowaniem lasera Nd:YAG do mikroobróbki diamentu. Zaprezentowano wpływ geometrii skupionej wiązki laserowej na obróbkę diamentu.

EN

Laser machining has become more and more cost and time effective method of diamond machining. Application of high pulse energy laser sources, as Q - switched lamp pumped Nd:YAG (λ = 1064nm) and DPSS Nd:YAG KTP (λ = 532nm), results in a high productivity and a very good cutting edge and surface quality in relation to a level of the capital investment and the cost of maintenance. The paper presents results of approach to diamond micromachining, related to application of DPSS Nd:YAG KTP (λ = 532nm) laser. The role of the focused laser beam waist area in diamond machining is described. The Rayleigh effective length was roughly assumed as a distance-determining Tool Affected Zone.

13

Superconductivity in covalent semiconductors

88%

Iakoubovskii K.

Open Physics

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2009

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tom 7

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nr 4

654-662

EN

This review covers recent advances in superconductivity of diamond, Si, SiC, group III–V and II–IV semiconductors, metal-intercalated graphite and fullerites. The results are critically analyzed and prospects are given for future research directions. In particular, it is argued that the highest transition temperatures of ∼9 K in diamond and 11.5 K in CaC6 can further be enhanced and that no reliable evidence exists yet for superconductivity in III-V semiconductors.

14

The origin of the G-line in the CVD diamond Raman spectrum

88%

Fabisiak K. , Rozpłoch F.

Karbo

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1998

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tom Nr 1-2

66-67

EN

This work presents the Raman and ESR spectroscopy investigation performed on the different quality CVD diamond films. Particularly the origin of the so-called G-line in the CVD diamond Raman spectrum is discussed.

PL

Własności fizyczne cienkich warstw diamentowych otrzymywanych metodami CID bardzo silnie zależą od parametrów samego procesu CVD. Głównym czynnikiem mającym najsilniejszy wpływ na jakość warstw diamentowych jest koncentracja węglowodoru podczas wzrostu warstw diamentowych w procesie CID. Przedstawione są wyniki badań cienkich warstw diamentowych przy użyciu spektroskopii Ramana i ESR. Szczególna uwaga poświęcona została dyskusji pochodzenia tak zwanej linü G w widmie Ramana cienkich warstw diamentowych.

15

Diament jako materiał przetwornikowy do produkcji biosensorów

75%

Mosińska L. , Fabisiak K. , Paprocki K. , Kowalska M. , Popielarski P. , Szybowicz M. , Stasiak A.

Przemysł Chemiczny

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2013

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tom T. 92, nr 6

919--923

16

Centra barwne azot-wakancja w diamencie - od klejnotów do technologii kwantowych

75%

Mrózek M. , Wojciechowski A. M. , Gawlik W.

Postępy Fizyki

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2023

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tom T. 74, z. 1

2--13

PL

Diamenty zachwycają doskonałym pięknem i niezwykłymi właściwościami. Najczęściej kojarzone są z branżą jubilerską lub z zastosowaniem w przemyśle szlifierskim. Najciekawsze i najważniejsze własności diamentów związane są z tym, że możemy je badać i modyfikować do nietypowych zastosowań. W szczególności specyficzne defekty diamentu, centra barwne azot-wakancja, otwierają niezwykle ciekawe możliwości, z których kilka opisujemy poniżej. W artykule omówione zostały podstawowe właściwości diamentów, ich pochodzenie i metody sytetyzowania, a także niedoskonałości struktury krystalicznej diamentu, które mogą wykazywać nowe właściwości optyczne i spektroskopowe. Druga część artykułu prezentuje strukturę i właściwości jednego z takich defektów - centrum barwnego azot-wakancja (NV). W końcowej części omówione zostały praktyczne zastosowania centrów NV w charakterze czujnika wielkości fizycznych takich jak pole magnetyczne i temperatura, a także w dziedzinie przetwarzania informacji kwantowej - być może zaowocuje to powstaniem komercyjnego komputera kwantowego zbudowanego na ciele stałym.

EN

Diamonds impress with their perfect beauty and extraordinary properties. They are most often associated with the jewellery industry or with the use in grinding industry. The most interesting and important ones can be studied and modified. In particular, specific diamond defects, the nitrogen-vacancy color centers, have extremely interesting properties. They also allow for very attractive applications, some of which are described below. Here we discuss the basic properties of diamonds, their origin, and methods of synthesis, as well as the defects of their crystal structure, which may exhibit exciting new optical properties. In the second part of the article, we focus on the structure and properties of one such defect - the nitrogen-vacancy (NV) color center. The following parts present some practical applications of NV centers as sensors of physical quantities such as magnetic field and temperature, as well as in the field of quantum information processing. The latter option opens a window to the construction of a commercial solid-state quantum computer, which would be a great help in mass production.

17

Changes in glioblastoma multiforme ultrastructure after diamond nanoparticles treatment. Experimental model in ovo

75%

Grodzik M.

Annals of Warsaw University of Life Sciences - SGGW. Animal Science

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2013

|

tom 52

EN

Experimental model in ovo. Glioblastoma multiforme (GBM) is the most common primary malignancy in the brain and confers a uniformly poor prognosis. Despite decades of research on the topic, limited progress has been made to improve the poor survival associated with this disease, new therapeutic strategies are still needed. The application of nanotechnology to disease treatment, diagnosis, monitoring, drug delivery platform and to the control of biological systems is promising, also in cancer therapy. Diamond na-noparticles (DN) are bioactive substance toward glioma tumour cultured on the chicken embryo chorioallantoic membrane (CAM). DN reduce tumor mass and volume and inhibited new blood vessel development in glioma tumor. In the present experiment we additionally observed, that DN caused changes in the tumor ultrastructure testify to the ongoing process of cell death, probably carried out by autophagy.

PL

Zmiany w ultrastrukturze glioblastoma multiforme po zastosowaniu nanocząstek diamentu. Badania modelowe in ovo. Glioblastoma multiforme (GBM) jest najczęściej występującym złośliwym nowotworem pierwotnym mózgu o bardzo złych rokowaniach. Pomimo dekad lat badań na tym problemem, niewielki postęp został uczyniony aby wydłużyć życie chorym, nowe strategie terapeutyczne są nadal poszukiwane. Zastosowanie nanotechnologii w leczeniu chorób, diagnostyce, monitornigu, platformach dostarczania substancji aktywnych i kontroli systemów biologicznych daje nadzieję na poprawę aktualnej sytuacji, również w terapii nowotworów. Nanocząstki diamentu (DN) są bioaktywnymi substancjami w stosunku do guza mózgu hodowanego na błonie kosmówko-wo-omoczniowej zarodka kury. DN redukuje masę i objętość guza oraz hamuje rozwój nowych naczyń krwionośnych (angiogenezę). W prezentowanym doświadczeniu dodatkowo zaobserwowano zmiany w ultrastrukturze komórek guza pod wpływem działania nanocząstek diamentu, które świadczą o zachodzących procesach śmierci komórkowej, prawdopodobnie na drodze autofagii.

18

Zaawansowane modelowanie warstw diamentowych CVD w zastosowaniach MEMS/MOEMS

75%

Kociubiński A. , Duk M. , Bieniek T. , Janczyk G.

Przegląd Elektrotechniczny

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2010

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tom R. 86, nr 7

221-223

PL

W artykule przedstawiono i omówiono zastosowanie warstw diamentowych osadzanych metodą CVD w systemach typu MEMS i MOEMS. Porównano fizyczne właściwości warstw diamentowych z właściwościami krzemu. Jako przykład przedstawiono założenia i wyniki symulacji typowej struktury mikromechanicznej wytworzonej z warstwy diamentowej i warstwy krzemowej. Wszystkie symulacje zostały wykonane dedykowanym oprogramowaniem do symulacji systemów typu MEMS - CoventorWare ™.

EN

of CVD diamond layers have been compared with silicon layer properties. As an example of diamond-based and silicon-based devices, modeling issues and results of simulations performed for typical MEMS structure have been presented and discussed. All simulations have been carried out within the specialized simulation environment - CoventorWare™.

19

Analiza przewodności cieplnej diamentu oraz cienkich warstw DLC

75%

Gęsikowska E. , Dudek M.

Inżynieria Materiałowa

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2010

|

tom Vol. 31, nr 4

965-968

PL

Autorzy rozważają przydatność rożnych modeli matematycznych do analizy fononowego przewodnictwa cieplnego w kryształach diamentu oraz warstwach DLC. Otrzymane wyniki dowodzą, iż modele Callaway'a i Hollanda wykazują najlepszą zgodność z danymi doświadczalnymi uzyskanymi dla diamentu typu IIa. Wynik ten jest intuicyjnie oczywisty, gdyż struktura diamentu typu IIa jest najbardziej zbliżona do idealnej. W przypadku diamentu typu I i IIb, zawierającego odpowiednio domieszki azotu i boru, zmienia się przewodność cieplna, a tym samym w analizowanych modelach niezbędne są poprawki. Modyfikacje te stanowią pierwszy krok do stworzenia komplementarnego modelu przewodnictwa cieplnego uwzględniającego strukturę i morfologię warstw DLC, zmieniającą się w bardzo szerokim zakresie w zależności od metody ich wytwarzania.

EN

The authors consider the applicability of some various mathematical models to the analysis of thermal conduction in bulk diamond crystals and thin DLC films. The results obtained in this investigations show that Callawy's and Holland's models have the best fit to data of diamond of type IIa. This result is intuitionally obvious since the structure of diamond of type IIa is the most similar to the ideal structure. In case of diamond of type I and IIb, which contain dopes of nitrogen and boron respectively, the thermal conductivity is change and corrections must be introduced in analyzed models. Those modifications are the first step to create a complementarily model of thermal conduction, in which it is taken into account the structure and the morphology of thin DLC films which are changed in a very wide range in dependence on the method of its deposition.

20

Applicability of microwave plasma CVD and electrochemical process for deposition of diamond-related thin films

75%

Kulesza S. , Madaj D.

Elektronika : konstrukcje, technologie, zastosowania

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2009

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tom Vol. 50, nr 1

56-58

EN

Microwave plasma CVD and electrochemical method have been described and analyzed in the paper taking into consideration their feasibility of growing diamond-based structures.

PL

W pracy przedstawiono wykorzystanie metody osadzania chemicznego z fazy gazowej (MP-CVD) oraz metody elektrochemicznej pod kątem odkładania struktur węglowych o dominującej hybrydyzacji tetraedrycznej (diamentopodobnych).