Key Engineering Materials Vol. 437

Abstract: For an optimum performance of MEMS devices such as microactuators and microsensors based on piezoelectric thin films a Si/Ti/Pt bottom electrode is widely used. This study shows temperature dependence of surface morphology of both platinum bottom electrode and piezoelectric lead titanate zirconate (PZT) thin films. Ti (10 nm) and Pt (100 nm) thin films were deposited on silicon substrate by thermal evaporation and electron beam, respectively, without vacuum breaking. After annealing treatment, the Pt film exhibited (111) preferred orientation. Finally a 0.8 micron thick PZT (54/46) films were deposited by r.f. magnetron sputtering at room temperature in pure Ar followed by a conventional post annealing treatment on silicon substrate. The XRD measurements have shown the perovskite structure of PZT films with (100) preferred orientation growth. The roughness of platinum film measured by AFM test showed the continuous smoothness of platinum surface for different annealing temperatures. The SEM test results demonstrated that irrespective of the annealing temperature increases, recrystallization of platinum and nano-size holes on Pt surface occurred. The latter caused the acceleration of out-diffusion titanium atoms through Pt layer and reach to the other side of surface. The surface state of Pt thin film is very important as it could strongly influence the PZT surface morphology so the existence of bubbles and depression on PZT surface are increased with both recrystallization of Pt grains and nano-size holes on Pt film surface when the annealing temperature increased.

Abstract: Most colloidal samples have a non-negligible imaginary component of the effective refractive index due to scattering and absorption losses. In this paper we analyze the requirements on a differential refractometer so that it can be used to measure the real part of the effective refractive index increment in colloids for particle size analysis.

Abstract: The national metrology, standards and conformity assessment system in Ukraine is still largely based on the state-controlled Soviet system and differ significantly in form and function from the national standards and conformity assessment systems (or the national quality infrastructure) found in countries of the European Union and of the OECD. While in the latter group of countries the vast majority of national standards are of a voluntary nature and the national quality infrastructure operates as a highly-decentralized network of public and private institutions, the Ukrainian model emphasizes technical regulations (or mandatory standards) and is dominated by highly-centralized government institutions. Recent accession of Ukraine into WTO and commitment for integration into the European Union (EU) motivated an assessment of its national quality infrastructure (metrology, standards and conformity assessment). The importance of metrology and metrology policy development is discussed to support the regulatory environment. The paper discusses main findings of the assessment developed in cooperation between the World Bank and the IFC Ukraine Business Enabling Environment Project.

Abstract: High numerical aperture focusing is becoming increasingly important for nanotechnology related applications. Rigorous, vector evaluation of the focused field, in such cases, is usually performed using the Richards-Wolf method which is based on the Debye approach. The resulting field is known to have a piecewise quasi planar phase. A corresponding result, produced by a Fresnel-Kirchhoff integral for aplanatic optical systems of medium and low numerical apertures, leads to the well known physical fact that a quadratic phase exists when the entrance pupil is not located at the front focal plane. Yet, the amplitudes produced in both ways are in a good agreement. In this work we investigated the difference, presented above, in a 2D system with the help of the Stratton-Chu diffraction integral. The amplitude obtained by the Stratton-Chu integral was quite similar to the classic results while the phase exhibited a quadratic behavior, with the quadratic coefficient depending on the numerical aperture of the optical system. For lower numerical apertures it approached the result obtained by the Fresnel-Kirchhoff integral while for higher numerical apertures it was approaching the Richards-Wolf result. A mathematical expression for the quadratic coefficient was derived and verified for various values of numerical aperture.

Abstract: The construction and principle of operation of the torsion magnetic variometer are discussed, some specificities of magnetic sensor such as different variants of hanger systems, brace types and magnet proportions are shown.

Abstract: The article describes the device for manufacturing torsion bars with helical anisotropy, performed as a braid made of Kevlar filaments (fibers). Physical and kinematic configurations are demonstrated, operation concept of the device is described. Characteristics of produced torsion bars are discussed.

Abstract: In modern sciences and technologies it is required to investigate local atomic and electron structure of matter independently on its aggregate state. There are advanced methods aimed at short order. These methods are based on the phenomena accompanied by interference of secondary electrons excited by primary X-ray radiation. Such methods are known as XAFS (X-ray absorption fine structure). These methods are based mainly on using of synchrotron radiation. It is realized in two modes: ‘transmission mode’ and registration of secondary effects that follow the primary X-ray absorption. One may announce only two such effects: X-ray induced fluorescence and X-ray induced electron emission (photoeffect). However, the access to synchrotron rings is problematic for the most users. This fact supposes the necessity to develop laboratory devices of direct urgent access. Since the power of laboratory X-ray sources is much less than the flux from synchrotrons, it is necessary to use secondary electron detectors of considerably higher efficiency. Moreover, it is attractive to possess energy in spatial resolution. Channeltrons and multi-channel plates do not have such abilities. That is why the advanced electron detector was developed and exposed to photoeffect under acceleration field. The work is performed within the frames of ISTC Project #3157.

Abstract: A model of absolute measuring instrument of power of synchrotron radiation in soft X-ray range of wavelengths of 8 – 0.4 nm based on high-temperature superconductor bolometer with electrical substitution has been developed, fabricated and tested. Tests have been carried out at the synchrotron radiation (SR) station “Cosmos” on the VEPP-4 storage ring of Budker Institute of Nuclear Physics of the SB RAS. It was ascertained that sensitivity of the device allows carrying out measurements of an SR flux power in the given spectral range. The minimum measured power was 3.2 W. A predicted threshold sensitivity of bolometer ~10-10 W/Hz1/2 at modulation frequency of 10 Hz and analysis of other factors influencing the measurement accuracy prove it to be real to achieve a 1 % accuracy at measurement of SR flux power of about 1 W.

Abstract: The project ISTC “SPECTROMETRIC POSITION SENSITIVE DETECTOR WITH BASE ENERGY SHIFT” is interesting for creation new area semiconductor detector device for EXAFS spectroscopy, for traditional X-ray diffractometry (XRD), as well as Small-Angle X-ray Scattering diffractometry (SASX). Diffractometry methods allow creating original features of position sensitive detector. Crystallography quality of silicon multi layer detector with original photo mask was examined by XRD and SAXS with ordinary scintillation detectors. Grazed incidence SAXS (GISAXS) provides information both about lateral and normal ordering of multilayers at a surface or inside a thin epitaxial film [1]. Using high-energy X-ray source (rotating anode or synchrotron radiation in future) and high adjustment monochromator SAXS rocking curves in transition and reflection mode had been received. It allows obtaining the information of 3D size lamellar or column-like domains. Results of an experimental investigation of the size layer structure are presented.