Influence of doping effect of Cu ions on the elastic prperties of the LiNbO3 crystal in were studied by the Brilloui light scattering method. Dopant concentration of Cu was equal to 0.05mol%. Comparison with pure samples shower relative decrease in frequencies falling in the range od 4-11%. Measurements were done in defferent scattering configurations.
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A new wide-band frequency component in the Brillouin spectrum, arising from absorption, has been detected in the SLAO oxide crystal. This completes the typical Brillouin spectrum, where Rayleigh lines, inelastic Stokes and anti-Stokes lines have been observed as a result of scattering from bulk acoustic phonons and, for some experimental configurations, on surface acoustic phonons. This newly discovered spectral component is distributed uniformly in frequency, independently of the light power incident on a sample, and depends on the incident wavelength.
Some results and predictions for the acoustic wave speed changes in the LiNbO3 crystal doped by the Cu atoms are presented. A simple model predicts small changes of elastic properties for technologically available dopant concentrations. Results of hypersonic experiments of the Brillouin light scattering type are given. Measured values of elastic constants and acoustic wave frequencies show no large changes in comparison to theoretical predictions. A small discrepancy is caused by doping process, what affects crystal stoichiometry, changes atom distances as well as modifies its elastic features.
In the paper the idea of testing of athmospheric air by photoacoustic method i presented. The base of photoacoustic effect theory in gas is presented. The paper concerns also preliminary results of photoacoustic experimental investigation, too.
Influence of doping effect of Cu ions on the elastic properties of the LINBO3 crystal in were studied by the Brillouin light scattering method. Dopant concentration of Cu was equal to 0.05mol%. Comparison with pure samples showed relative decrease in frequencies falling in the range of 4-111%. Measurements were done in different scattering configurations.
W pracy przedstawiono sposób postępowania przy wyznaczaniu kompletu stałych sprężystych materiału o symetrii rombowej metodą rezonansową. Metoda rezonansowa została zastosowana dla cienkich płytek kołowych o swobodnym brzegu, podpartych w czterech punktach na przecięciu linii węzłowych pierwszego i drugiego rezonansu. W opisanym układzie pomiarowym próbka wykonuje drgania giętne pobudzana metodą elektrostatyczną. W pracy podane są również równania określające częstotliwości drgań dla anizotropowych płytek kołowych o różnej orientacji krystalograficznej. Zaproponowany sposób postępowania został zweryfikowany doświadczalnie przy wykorzystaniu do badań monokryształów NaKCl4H4O6*H2O.
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The resonance method for determination of elastic constant set of rhombohedral crystals is presented. The resonance method has been applied to thin, circular plates with free edge, supported in four crossing points of nodal lines of the first and the second resonance. In described system the sample performs flexural vibrations and is excited by electrostatic method. In the paper expressions for vibration frequencies of anisotropic angular plates with different crystaliographic orientations are given. The proposed method has been verified experimentally for NaKCI4H4O6*H2O monocrystals. t^
W pracy zaprezentowano nową komórkę fotoakustyczną, zaprojektowaną i zbudowaną w Instytucie Fizyki Politechniki Śląskiej. Komórka ta jest przeznaczona do badania próbek ciał stałych. Przy obecnie zastosowanych oknach badania można prowadzić w zakresie widmowym od bliskiej podczerwieni do bliskiego nadfioletu przy modulacji ciągłej lub impulsowej.
EN
The new photoacoustic cell designed and built in the Institute of Physics of the Silesian Technical University is presented in the work. This cell is destined to solid states samples investigations. With actually used windows these investigations can be carried out in the spectral range from near infrared to near ultraviolet and with continuous and pulse modulations.