Peritektični čelici: značajke strukture, tehnologije legiranja i primjene

The article presents analysis of phase transformation characteristics, primary structure formation, alloying technology and usage of steels, which undergo a peritectic transformation during their solidification.U članku se predočuje analiza značajki fazne transformacije, nastanka primarne strukture, tehnologije legiranja i primjene čelika podvrgnutih peritektičkoj transformaciji pri skrućivanju

Elastic Mid-Infrared Light Scattering: a Basis for Microscopy of Large-Scale Electrically Active Defects in Semiconducting Materials

A method of the mid-IR-laser microscopy has been proposed for the investigation of the large-scale electrically and recombination active defects in semiconductors and non-destructive inspection of semiconductor materials and structures in the industries of microelectronics and photovoltaics. The basis for this development was laid with a wide cycle of the investigations on the low-angle mid-IR-light scattering in semiconductors. The essence of the technical idea was to apply the dark-field method for spatial filtering of the scattered light in the scanning mid-IR-laser microscope. This approach enabled the visualization of large-scale electrically active defects which are the regions enriched with ionized electrically active centers. The photoexcitation of excess carriers within a small volume located in the probe mid-IR-laser beam enabled the visualization of the large-scale recombination-active defects like those revealed in the optical or electron beam induced current methods. Both these methods of the scanning mid-IR-laser microscopy are now introduced in detail in the present paper as well as a summary of techniques used in the standard method of the lowangle mid-IR-light scattering itself. Besides the techniques for direct observations, methods for analyses of the defect composition associated with the mid-IR-laser microscopy are also discussed in the paper.Comment: 44 pages, 13 figures. A good oldi

Terahertz conductivity of Si and of Ge/Si(001) heterostructures with quantum dots

With an MBE technique, a Si/Ge heterostructures are prepared containing layers of nanostructured Ge with quantum dots of size of several nanometers. The effective conductivity of the layers is determined by a quasioptical terahertz-subterahertz coherent source BWO spectroscopy. The conductivity is found to be strongly enhanced compared with the conductivity of bulk germanium. Possible microscopic mechanisms responsible for the enhancement will be discussed. Application of BWO spectrometers for obtaining precise quantitative information on of dielectric properties at THz-subTHz frequencies of semiconducting layers and structures is demonstrated by presenting the temperature dependences of dielectric characteristics of a commercial silicon wafer at frequencies 0.3 to 1.2 THz and temperatures 5K-300K.Comment: Proc. 33rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz 2008), September 15-19, 2008, California Institute of Technology, Pasadena, California, USA

Absorption of Terahertz Radiation in Ge/Si(001) Heterostructures with Quantum Dots

The terahertz spectra of the dynamic conductivity and radiation absorption coefficient in germanium-silicon heterostructures with arrays of Ge hut clusters (quantum dots) have been measured for the first time in the frequency range of 0.3-1.2 THz at room temperature. It has been found that the effective dynamic conductivity and effective radiation absorption coefficient in the heterostructure due to the presence of germanium quantum dots in it are much larger than the respective quantities of both the bulk Ge single crystal and Ge/Si(001) without arrays of quantum dots. The possible microscopic mechanisms of the detected increase in the absorption in arrays of quantum dots have been discussed.Comment: 9 pages, 4 figures; typos correcte

Вплив форми аустеніту на властивості стали Р6М5

The influence of the form of austenite formed during rapid crystallization on the properties of P6M5 steel is studied. The phase composition and structure of the steel after heat treatment are studied.Исследовано влияние формы аустенита, образующегося при быстрой кристаллизации, на свойства стали Р6М5. Исследованы фазовый состав и структура стали после термической обработки. Досліджено вплив форми аустеніту, що утворюється при швидкій кристалізації, на властивості стали Р6М5. Досліджено фазовий склад і структура стали після термічної обробки.

The solidificaiton mechanism and special features of the primary structure of nickel-based creep-resistant alloys

Translated from Russian (Probl. Spetsial'noi Elektrometallurgii 1999 (1) p. 54-59)SIGLEAvailable from British Library Document Supply Centre-DSC:9023.190(VR-Trans--8936)T / BLDSC - British Library Document Supply CentreGBUnited Kingdo