National Institute Of Materials Physics - Romania

Publications

5781 articles found

3561. Thickness-driven antiferroelectric-to-ferroelectric phase transition of thin PbZrO3 layers in epitaxial PbZrO3/PbZr0.8Ti0.2O3 multilayers (vol 91, art no 122915, 2007)

Authors: Boldyreva, K; Pintilie, L; Lotnyk, A; Misirlioglu, IB; Alexe, M; Hesse, D

Published: NOV 12 2007, APPLIED PHYSICS LETTERS, 91, DOI: 10.1063/1.2811708

3562. CMS physics technical design report: Addendum on high density QCD with heavy ions

Authors: Chatrchyan, S; Hmayakyan, G; Sirunyan, AM; (...) Lungu, GA; (...) Zabi, A (CMS Collaboration)

Published: NOV 2007, JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 34, 2307-2455, DOI: 10.1088/0954-3899/34/11/008

This report presents the capabilities of the CMS experiment to explore the rich heavy-ion physics programme offered by the CERN Large Hadron Collider (LHC). The collisions of lead nuclei at energies root(NN)-N-S = 5(5 TeV, will probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research is to study the fundamental theory of the strong interaction - Quantum Chromodynamics (QCD) - in extreme conditions of temperature, density and parton momentum fraction (low-x). This report covers in detail the potential of CMS to carry out a series of representative Pb-Pb measurements. These include \"bulk\" observables, (charged hadron multiplicity, low p(T) inclusive hadron identified spectra and elliptic flow) which provide information on the collective properties of the system, as well as perturbative probes such as quarkonia, heavy-quarks, jets and high p(T) hadrons which yield \"tomographic\" information of the hottest and densest phases of the reaction.

3563. Thickness oscillation effect in photoexpansion and photocontraction of amorphous selenium

Authors: Popescu, M; Sava, F; Shimakawa, K; Ikeda, Y; Babin, V

Published: NOV 2007, JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS, 9, 3562, DOI:

Thickness oscillations under light irradiation or by switching-off the light have been revealed in amorphous selenium films. The explanation was given in the frame of a theory that takes into account the balance between the expansion of the inter-chain distance due to electrical charging and better ordering of chains due to freedom of chains to accommodate into the structure as a result of the diminishing or increasing of the spatial hindrance.

3564. Hydroxyapatite-iron oxide bioceramic prepared using nano-size powders

Authors: Predoi, D; Barsan, M; Andronescu, E; Vatasescu-Balcan, RA; Costache, M

Published: NOV 2007, JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS, 9, 3613, DOI:

The hydroxyapatite (HAp) is an important material for orthopedics and dentistry applications. In the present study a simple method was tried for added the iron oxide nanoparticles into HAp so as to establish and induce a biocompatibility. In the research the mechanism of the coated of iron oxide with HAp would also be described by the analysis of X-ray diffractometer, scanning electron microscope and Fourier transformation infrared. Osteoblast cells were permanent monitored to detect any possible influence due to samples that might alter the cell growth, viability and proliferation.

3565. Interfacial tension of some liquid crystals in the cyanobiphenyl series at the interface with glycerol

Authors: Beica, T; Moldovan, R; Zgura, I; Frunza, S

Published: NOV 2007, JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS, 9, 3627, DOI:

The temperature dependence of the interfacial tension for three compounds from the homologous series of alkylcyanobiphenyl (nCB), 5CB, 7CB and 8CB, at the interface with glycerol was measured in a temperature range from mesomorphic to isotropic phase. The drop shape method of measure was used. The interfacial tension of all the studied liquid crystals presents an anomalous behaviour with maximum and small upward jumps at the phase transitions, in rising temperature.

3566. Multiple wavelength InGaAs quantum dot lasers using ion implantation induced intermixing

Authors: Mokkapati, S; Du, S; Buda, M; Fu, L; Tan, HH; Jagadish, C

Published: NOV 2007, NANOSCALE RESEARCH LETTERS, 2, 553, DOI: 10.1007/s11671-007-9097-x

We demonstrate multiple wavelength InGaAs quantum dot lasers using ion implantation induced intermixing. Proton implantation, followed by annealing is used to create differential interdiffusion in the active region of the devices. The characteristics (lasing-spectra, threshold currents and slope efficiencies) of the multi-wavelength devices are compared to those of as-grown devices and the differences are explained in terms of altered energy level spacing in the annealed quantum dots.

3567. High k materials used to manufacture miniaturised dielectric antennas for military applications

Authors: Nicolaescu, I; Ioachim, A; Toacsan, I; Radu, I; Banciu, G

Published: NOV 2007, JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS, 9, 3597, DOI:

The microwaves are used for both civilian and military applications for communication and detection. Due to the emerging applications and the need for more bandwidth as well as for high speed there is a strong competition for ultra high frequencies devices. As it is know the size of different kind of microwave components is in a certain relation with the wavelength divided by root square of the dielectric permittivity. So the size of microwave component can be decreased by increasing the dielectric permittivity. Dielectric materials based on TiO2 are recommended for applications in electromagnetism and optics due to their nonlinear properties, to high value of the dielectric permittivity and their temperature behavior. The paper describes very shortly the technology applied to manufacture high dielectric permittivity materials based on TiO2 and microwave devices designed with this. In addition, the experimental data measured for a dielectric antenna are presented.

3568. Acylation of different amino derivatives with fatty acids on UL-MFI-type catalysts

Authors: Musteata, M; Musteata, V; Dinu, A; Florea, M; Hoang, VT; Trong-On, D; Kaliaguine, S; Parvulescu, VI

Published: NOV 2007, , DOI: 10.1351/pac200779112059

3569. (Te/SnSe2)(3) multilayers deposited by pulsed laser deposition. Structure and gas sensing properties

Authors: Lorinczi, A; Sava, F; Tomescu, A; Simion, C; Socol, G; Mihailescu, IN; Popescu, M

Published: NOV 2007, JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS, 9, 3492, DOI:

Multilayers made of alternative layers of composition SnSe2 and tellurium (three pairs) have been prepared by pulsed laser deposition (PLD). The complex films have been investigated by X-ray diffraction. After a special annealing in oxygen fluence at various temperatures, up to 620 degrees C, the films were investigated both by X-ray diffraction and for gas sensing. Gas sensing properties were tested for water vapours, carbon monoxide (CO) and methane (CH4). After annealing at high temperature, the structure of the multilayer samples show oxide phases like TeO2, SnO2 and a mixed oxide ternary phase SnTe3O8. The annealed multilayers show good sensing properties to water vapours and CO gas.

3570. The study of the passive film formed on the surface of 316L stainless steel in artificial physiological media

Authors: Tutunaru, B; Patru, A; Bibicu, I; Preda, M

Published: NOV 2007, JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS, 9, 3404, DOI:

This work is aimed at providing a better understanding of the biocompatibility of 316L stainless steel in the human body, where various biomolecules are able to bind metal ions and convey them from the surface of orthopaedic implant to various parts of the body. The passivation behavior of orthopaedic 316L implant was studied by associating the electrochemical methods (Differential Pulse Voltammetry and Cyclic Voltammetry) with the surface M(Mossbauer spectroscopy as a function of type of physiological media; glucydic, proteic and lipidic. Was studied the electrochemical behaviour of steel in three artificial media: Aminosteryl, Intralipid and Kabiven in the concentrations corresponding to the administration dosages. The results were discussed in the context of the formation of passive film which stability strongly depends on the corrosive activity of the physiological media in the order: Aminosteryl < Kabiven < Intralipid.