Wyniki wyszukiwania - Biblioteka Nauki

1

Properties of NiTi - shape memory alloy after modification by RF PCVD method

100%

Czerniak-Reczulska M. , Couvrat P. , Grabarczyk J. , Niedzielski P.

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2006

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tom R. 9, nr 56-57

37-39

EN

The DLC (diamond-like carbon) and NCD (nanocrystalline diamond) layers coat made implants of medical steel 316L, titanium and titanium alloys. These layers have excellent properties such as: high hardness, good biocompatibility to various types of cells, good adhesion to implants, wheres implants with diamond layer have good corrosion resistance in body fluids. Result received for these materials are encourage to modification other materials for example shape memory alloy NiTi, Nitinol is often used material in interventional cardiology, orthodontics and urology. Shape memory alloy characterizes of return to designed shape, superelasticity, thermomechanical behavior. This phenomenons are proceeded thanks to the martensite transformation. Modification in high temperature perhaps cause failure martensite transformation which influence on the material properties change.

2

CVD diamond: from growth to application

86%

Fabisiak K. , Staryga E.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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tom Vol. 37, nr 2

264-269

EN

Purpose: The main purpose of these studies was to give a short review of basic diamonds properties and indicate possibilities of different applications of this material. As an example, the application of CVD (Chemical Vapour Deposition) diamond layer in electrochemistry was shown. Design/methodology/approach: The diamond layers were synthesized using Hot Filament CVD (HF CVD) technique from a mixture of methanol and hydrogen. The physical and electrochemical properties of the obtained layers were studied by Raman spectroscopy and Cyclic Voltammetry (CV). Findings: It was shown that it is possible to synthesize the diamond layers of different morphology and quality. Raman microprobe measurements showed that quality of diamond films deposited by HF CVD method reflect their morphology. CV measurements showed that the fabricated electrodes had wide potential window almost twice bigger in comparison to the classical Pt electrode. Research limitations/implications: The interaction of diamond layers with chemical and biological environment is not complete. Practical implications: CVD diamond (synthetic diamond made by a chemical vapour deposition process) is an important family of materials used in microelectronic and optoelectronic packaging and for laser and detector windows. Its ultra-high thermal conductivity enables to increase microprocessor frequency and output power of microelectronic and optoelectronic devices. Diamond is resistant to chemical attack and chemical sensors based on the fact it can work in harsh environment. Originality/value: The paper underlines an important role of diamond films as a promising material for production of electrodes for electrochemical applications.

3

Field emission and microstructural characterization of diamond films deposited by HF CVD method

86%

Jarzyńska D. , Staryga E. , Znamirowski Z. , Fabisiak K. , Gotszalk T. , Woszczyna M. , Strzelecki W. , Dłużniewski M.

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tom Vol. 28

13-26

EN

Electron emission from diamond films (DF) deposited using HF CVD technique on silicon substrates has been studied. The field emission characteristics were analyzed using the Fowler-Nordheim model. The diamond films were also characterized by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Raman Spectroscopy (RS) and Electron Spin Resonance (ESR) techniques. The correlation between electron field emission of investigated films, Raman spectra and concentration of paramagnetic centres has been discussed. The electron emission properties of diamond films improved after doping with nitrogen. The field emission was obtained at turn-on electric field equal to about 10 V/µm and about 3 V/µm, for undoped diamond films and N-doped diamond films, respectively. It seems that the change of turn-on field values and other emissive properties of thin diamond layers may be caused by different content of non-diamond phase (e.g. graphite phase) induced by doping.

PL

Przeprowadzono badania emisji polowej z warstw diamentowych osadzonych przy użyciu metody HF CVD na podłożach krzemowych typu n i p. Charakterystyki emisyjne analizowano na podstawie modelu Fowlera-Nordheima. Wytworzone warstwy scharakteryzowano przy użyciu następujących metod: SEM, AFM, spektroskopii Ramana i Elektronowego Rezonansu Spinowego (ESR). Przeprowadzono dyskusję wyników, wskazując na korelację pomiędzy wynikami emisji polowej a koncentracją centrów paramagnetycznych oraz widmami ramanowskimi badanych warstw diamentowych. Zaobserwowano znaczną poprawę właściwości emisyjnych heterostruktur, w których warstwa diamentowa domieszkowana została azotem. Dla układów z niedomieszkowanymi warstwami diamentowymi wartość natężenia pola włączeniowego wynosiła około 10 V/ µm, zaś dla domieszkowanych azotem warstw diamentowych wartość ta równa jest 3 V/µm. Różnice w wartościach pola włączeniowego dla odpowiednich układów wynikają prawdopodobnie z różnej zawartości materii grafito-podobnej w badanych warstwach diamentowych. Warstwy domieszkowane azotem są silnie zdefektowane i zawierają znaczną ilość materii grafitopodobnej.

4

Growth of high quality diamond films on silicon substrate

72%

Benzhour K. , Nowak L. , Nowak Z. , Rozpłoch F.

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tom Nr 4

236-239

EN

Thin polycrystalline diamond films were deposited on prepared (100) Si substrate by hot filament chemical vapor deposition (HF-CVD). For all deposition processes, parameters as: substrate temperature, total pressure and gas flow were held on the same level. One sample was deposited using a method of three-step growth in HF-CVD chamber. Morphology investigations of diamond films using scanning electron microscopy (SEM), Raman spectroscopy (RS) and electron paramagnetic resonance (EPR) were performed. The EPR analysis revealed the presence of two kinds of paramagnetic centers related to diamond and nan-diamond phase.

PL

Polikrystaliczne warstwy diamentowe były osadzane metodą gorącego włókna z fazy gazowej (HF-CVD) na monokrystalicznym podłożu krzemowym o orientacji powierzchni (100). Temperatura podłoża, przepływy gazów i całkowite ciśnienie gazu były utrzymywane na stałym poziomie podczas wszystkich procesów osadzania. Jedna próbka była osadzana metodą trój stopniowego wzrostu w komorze HF-CVD. Morfologia i jakość uzyskiwanych warstw diamentowych były badane za pomocą elektronowej mikroskopii skaningowej (SEM), spektroskopii ramanowskiej (RS) i elektronowego rezonansu paramagnetycznego (EPR). Badania EPR ujawniły istnienie dwóch rodzajów centrów paramagnetycznych związanych z fazą diamentową i z fazą niediamentową.

5

The application of CVD diamond films in cyclic voltammetry

72%

Torz-Piotrowska R. , Wrzyszczyński A. , Paprocki K. , Screiber M. , Uniszkiewicz C. , Staryga E.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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tom Vol. 37, nr 2

486-491

EN

Purpose: The main purpose of these studies was to show the applicability of CVD (Chemical Vapour Deposition) diamond layer in electrochemistry and to work out the technology of manufacturing diamond electrodes. Design/methodology/approach: The diamond films were deposited on tungsten substrate by HF CVD technique, and then, their quality was checked by Raman spectroscopy. It was shown, using Cyclic Voltammetry (CV) measurements, that un-doped diamond films are chemically stable in aqueous solutions. Findings: The results of cyclic voltammetry measurements show that diamond electrode on tungsten substrate is electrochemically stable in aqueous solutions over a wide potential range (-3000 mV to 2000 mV). The Raman spectra confirmed the good quality of obtained diamond layer. Research limitations/implications: In particular, it was shown that diamond electrode showed a wide potential window, very low background current, chemical and physical stability. Practical implications: Presented results showed that CVD diamond films can find application in production of diamond electrodes for electrochemical application. The sensitivity of CVD diamond layers to the electroactive species indicates on possibility of application of this material for construction of chemical and biological sensors. Originality/value: The characteristics of diamond electrodes and the resistivity of this material to the chemical attack indicate that it can be employed in a number of electrochemical applications and additionally it can work in harsh environment. The HF CVD diamond layer seems to be the new, promising and versatile material for electrochemical applications.

6

Diamond-like carbon and diamond films as source of electron emission

72%

Staryga E. , Znamirowski Z. , Jarzyńska D. , Fabisiak K. , Banaszak A. , Cłapa M.

Karbo

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2005

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tom Nr 4

244-251

EN

We investigated electron field emission from diamond-like carbon and diamond thin layers. DLC and diamond films were deposited onto Si substrate using Radio Frequency Chemical Vapour Deposition process and Hot Filament Chemical Vapour Deposition technique, respectively. The field emission characteristics were described using the Fowler-Nordheim model. To analyze the surface morphology Raman spectroscopy, Electron Spin Resonance (ESR) and Scanning Electron Microscopy (SEM) was used. We obtained well-defined Raman spectrum peak for diamond films at 1332 cm-1.The Raman spectrum, for DLC layers, showed asymmetric peak consist of D and G-band around 1550 cm-1. It indicate for existence of sp3 (diamond) and s2 (graphite) phase in these films. The field emission for DLC films was obtained at turn-on electric field between 70-90 V/μ while for diamond films in a range between 60-140 V/μ. It seems that changes of turn-on field values and emissive properties of thin carbon layers may be cause by different content graphite phase in carbon films.

PL

Przebadano elektronową emisje polową węgla diamentopodobnego(DLC) i cienkich warstw diamentowych. Charakterystyki emisji polowej zostały opisane w oparciu o model Fowlera-Nordheima. Do analizy morfologii powierzchni zastosowano spektroskopię Ramana, elektronowy rezonans spinowy (ESR) oraz skaningowa mikroskopie elektronowa (SEM). Otrzymano wyraźne widma Ramana dla cienkich warstw diamentowych z maksimum przy 1332 cm-1. Widmo Ramana dla warstw DLC przedstawia asymetryczne składoweDorazG(1550 cm-1). Ta ostatnia świadczy o istnieniu faz sp3 (diament) oraz sp2 (grafit) w tych warstwach. Emisja polowa dla warstw DLC uzyskana była przy ustalonym na 70-90 V/μ.m natężeniu pola elektrycznego, zaś dla warstw diamentowych w przedziale 60-140 V/μm. Pomiary wskazują, że zmiany wartości przyłożonego pola i właściwości emisyjnych cienkich warstw węgla mogą być wywołane różną zawartością fazy grafitowej w warstwach węglowych.