The development of rocket technology and space research in Poland

A history of rocketry in Poland from the 14th century to present times is presented

Prediction of Anisotropic Single-Dirac-Cones in Bi1−x{}_{1-x}Sbx{}_{x} Thin Films

The electronic band structures of Bi${}_{1-x}$Sb${}_{x}$ thin films can be varied as a function of temperature, pressure, stoichiometry, film thickness and growth orientation. We here show how different anisotropic single-Dirac-cones can be constructed in a Bi${}_{1-x}$Sb${}_{x}$ thin film for different applications or research purposes. For predicting anisotropic single-Dirac-cones, we have developed an iterative-two-dimensional-two-band model to get a consistent inverse-effective-mass-tensor and band-gap, which can be used in a general two-dimensional system that has a non-parabolic dispersion relation as in a Bi${}_{1-x}$Sb${}_{x}$ thin film system

RHEED Intensity Oscillations During the Growth of Indium Ultrathin Films

The ultrathin high-purity single-crystal indium films with atomically flat surfaces, and precisely known thicknesses in UHV conditions were prepared These films were deposited on the Si(111)-(7×7) and Si(111)-(6×6)Au substrate cooled to temperatures up to 110 K. The growth of the indium films was studied by. reflection high-energy electron diffraction (RHEED). Pronounced specular beam intensity oscillations are found. The consequences for the understanding of RHEED intensity oscillations and of the growth of ultrathin films are discussed. The amplitude of the RHEED specular beam intensity oscillations as a function f the polar angle and temperature substrate Si was measured

Analysis of Shapes of RHEED Intensity Oscillations Observed for Growing Films

A new method of analysing shapes of RHEED intensity oscillations observed during epitaxial growth of ultrathin films is presented. The intensity of the specular electron beam is computed by solving the one-dimensional Schrödinger equation. The method can be used for interpreting data collected at very low glancing angle (< 1°) of the incident electron beam. In the paper we show numerically determined shapes of the intensity oscillations for different cases of settling of atoms at surfaces of growing films