Grzegorz Gladyszewski

Stress development during evaporation of Cu and Ag on Silicon

This work presents results of stress measurements during deposition of thin silver and copper films on 100 µm Si substrate. The stress in thin films has been determined by means of an optical system for the measurement of samples curvature. This system was applied in situ in a high vacuum deposition system. For Ag films the stress occurring during deposition goes from a low compressive value to tensile for thickness less than 30 nm and to compressive above this. For Cu films we observe tensile stress for thickness less 20 nm and above 50 nm. The same general trend of stress evolution with thickness is present in all cases at initial stage. There is the same growth mode for Cu and Ag because of the similar shapes of stress curves for thickness lower than 30 nm The behavior of stress evolution was explained by island nucleation and growth, island coalescence and continuous film growth. The difference in the stress evolution above 30 nm is caused by the fact that silver may be less sensitive than copper to adsorption of impurities. Adsorbed contamination inhibits compressive stress increase generated by grain boundary and defects remaining in the film.

Stress development during thin film growth and its modification under ion irradiation

The paper presents the results of average stress measurements during deposition of thin copper and silver films and during ion irradiation of molybdenum thin films. Deposition chamber and ion implanter were equipped with the same optical systems for radius of curvature measurement (scanning technique). The average stress in the 92 nm total thick Cu/Ag/Cu/Ag system on 100 μm Si substrate during deposition at room temperature is reported. Deposition process was intermitted after each material. The non-continuous changes of the stress are interpreted as differences in temperature of the sample in different deposition stages. High residual stresses up to 3 GPa were evidenced in the Mo thin films deposited on Si substrate with RF sputtering. During ion implantation with Kr and Ar ions stress relaxation effect of Mo thin films was observed. Kr ion irradiation of the silicon substrate without a film was additionally performed. After the irradiation (total dose 1.4 x 10 15 ions/cm 2 ), the implanted region of the silicon wafer was under compressive stress. A stress maximum was evidenced for a dose of 1 x 10 14 ions/cm 2 .

External barrel temperature of a small bore olympic rifle and shooting precision

Investigations on changes in a rifles barrel temperature during shooting in a rhythm typical for practitioners of Olympic shooting sports are presented. Walther KK300 (cal. 5.6 mm), a typical rifle often used in Olympic competitions, R50 RWS ammunition and a high speed thermographic camera were used in the study. Altair version 5 software was used to process thermal images and a stationary wavelet transform was applied to denoise signals for all the studied points. It was found that the temperature of the rifle barrel does not exceed 0.3°C after one shot whereas the total temperature increase does not exceed 5°C after taking 40 shots and does not affect the position of the hitting point on a target. In fact, contrary to popular belief, the so-called “warming shots” are not done for barrel heating but for cleaning of remnants in the barrel.

Stresses in Multilayer Systems: Test of the sin2Ψ Method

The sin 2 Ψ method based on the asymmetric X-ray diffraction is widely used to determine stresses in thin films. However, application of this method to multilayered thin films is not straightforward. In this work the authors present experimental asymmetric X-ray diffraction maps obtained for Cu/Ni and Au/Ni multilayered systems. They also describe the model based on a Monte Carlo simulation for calculating the X-ray diffraction profiles from multilayers.

Fast Fourier transform analysis as a new tool for Olympic rifle coaches

The aim of this study was to examine the possibility of using data collected with an electronic training system to determine the influence of a shooter’s heartbeat on shooting precision. Shooting sessions of a rifle in prone position were studied with the use of an electronic training system. As a case study, results of an experienced shooter were analyzed. Fast Fourier transform was applied to raw data extracted from the system and then results were interpreted. The spectrum obtained revealed a wide peak at the frequency f = 2.6 Hz that was considered as the second harmonics of the average frequency corresponding to the heartbeat decreasing down to 69 beats/min when releasing a shot. The session finished with a very modest score of 611.3 points. When a small intentional change in the shooter’s equipment (a sling position) was introduced, the spectrum obtained did not reveal any peaks and the shooter reached a much better score of 621.8 points. The use of fast Fourier transform analysis is proposed as a new tool for Olympic rifle shooters and coaches. This new tool does not require any complicated procedures and provides quantitative information on the influence of a heartbeat on the stability of a shooter’s aim.