Фазові рівноваги та фотоіндуковані зміни у системах Ag2S-In2S3-Si(Ge)S(Se)2

The nature of equilibria in the Ag2S–In2S3–Si(Ge)S2 systems was determined. The investigated vertical sections allow us to select the optimal conditions for the growth of the quaternary single crystals Ag2In2SiS6 and Ag2In2GeS6. Spectral distribution of the absorption coefficient and its photoinduced changes were studied. The possibility of using the investigated compounds as materials with controlled properties is demonstrated.У роботі встановлений характер рівноваг у системах Ag2S–In2S3–Si(Ge)S2 та досліджені політермічні перетини дозволяють вибрати оптимальні умови росту монокристалів тетрарних халькогенідів Ag2In2SiS6 і Ag2In2GeS6. Проведено дослідження спектрального розподілу коефіцієнта поглинання та його фотоіндукованих змін. Показано можливість використання досліджуваних сполук в якості матеріалів з керованими властивостями

Urbach’s edge of glassy HgSe-GeSe₂ alloys: static disorder and temperature dependence of optical absorption

Results of investigations of spectral characteristics in the fundamental absorption range for the glass-like alloys HgSe - GeSe₂ are represented. To explain the phenomenon of anomaly growth of the static disorder, the model of deforming tensions is discussed. The hypothesis concerning a sharp change of physical-and-chemical properties for the transition over the double eutectic point on the stable phase diagram of the HgSe - GeSe₂ system with a changing glass-creating matrix is suggested

The structure of glassy HgS–GeS₂

The glass HgS(x)-GeS2(₁₀₀-x) (0 ≤ x ≤ 50) was subjected to X-ray analysis. The radial distribution functions were calculated using the integral Fourier transformation based on X-ray scattering curves. The average interatomic distances within the first and second coordination spheres were determined. It is suggested that the transformational changes of scattering curves are related to the emergence of heterogeneity due to Hg₄GeS₆ inclusions

Дослідження оптичного поглинання та п’єзоелектричного ефекту у монокристалі твердого розчину AgGaGe3Se7.6Te0.4

In present work spectral distribution of absorption coefficient in the range of 100 – 300 K was investigated and band gap values  evaluated. Parameters of Urbach rule were calculated and linearity  of temperature dependence of Urbach energy was showed. Thermo induced piezoelectric effect in a range of 297 ‑ 357 K was investigated. Laser induced kinetics of piezomodule was investigated and absence of irreversible changes was showed. Influence of heating the crystal during laser illuminating on piezoelectric module was adjusted.У даній роботі досліджено спектральний розподіл коефіцієнта поглинання в діапазоні температур 100 – 300 К, оцінена ширина забороненої зони. Показана експоненційна залежність коефіцієнта поглинання в області краю поглинання, розраховані параметри правила Урбаха. Досліджено температурно- та лазерно- індукований п’єзоелектричний ефект. Скорегован

Obtaining and optical properties of the glasses of the GeS₂–HgS system

The glassy alloys of the GeS₂–HgS system in the range of 0–50 mol. % HgS were obtained by the melt quenching technique. Their Raman spectra were investigated. The dependence of the particularities of the light scattering bands on the chemical composition was analyzed

Склосистема Tl2S – In2S3 – GeS2 як новітні перспективні матеріали для фотоніки

It was established that minimal content of the glass-forming component GeS2 is equal to 30 mol.% (by exploration the set of 23 different alloys with different composition). Correlation between structural properties, thermal parameters (glass transition, crystallization and melting temperatures) and optical absorption spectra along of the titled glasses system has been found. The temperatures, the band gap energy and the characteristic energy of vitreous alloys for the gastric system Tl2S‑In2S3‑GeS2 were investigated experimentally.Встановлено, що мінімальний вміст складоутворюючого компонента GeS2 дорівнює 30 мол.% (досліджували набір 23 різних сплавів з різним складом). Встановлено взаємозв'язок між структурними властивостями, термічними параметрами (температура склa, температури кристалізації та плавлення) та оптичними спектрами поглинання. Експериментально досліджені температури, енергія розриву смуг та характерна енергія склоподібних сплавів для системи Tl2S‑In2S3‑GeS2

Influence the cationic substitution in AgGaGe₃Se₈ on the electro-optical, IR optical and nonlinear properties

In present article we present results of detailed study of the possibility adapting AgGaGe3Se8 single crystal properties to desired requirements by investigate the influence of the different cationic substitution on the physical properties: optical, nonlinear optical (NLO) - Second Harmonic Generation (SHG) and temperature dependent photoconductivity. We report results obtained for modified crystals based on AgGaGe₃Se₈ by cationic substitution of the elements belong to first - (Ag-Cu), third (Ga-In), and fourth (Ge-Sn) groups of the periodic system. For the convincing observation the effects of various impurities and compare results with obtained for virgin AgGaGe₃Se₈ crystal was conducted replacing at 5 mol. % one element by another

Transport Phenomena In Single Crystals Tl1−XIn1−XGeXSe2 (x=0.1, 0.2)

Temperature dependences of electroconductivity for single crystals Tl1−xIn1−xGexSe2 were analyzed. It was established an occurrence of thermoactivated states within the temperature range 100-300 K. The conductivity is formed by delocalized carriers within the conductivity band and the jumping conductivity over the localized states which are situated in the narrow localized states near the Fermi level. Following the performed data the activation energy was evaluated with accuracy up to 0.02 eV. The density of the localized states as well as the distribution of the energy over the mentioned states was evaluated. Additionally the average distance between the localized states is evaluated at different temperatures