A. Yu. Mityagin

Ultraviolet photodetectors based on natural diamond

Ultraviolet photodetectors based on natural 2a diamond are fabricated and examined. From the capacitance-voltage characteristics and capacitance spectra, it is found that the ac conductivity of photodetectors is purely capacitive and that the capacitance of the samples is determined by their geometry. The dynamic range of the photodetectors is found to be no less than 104. The measured photosensitivity spectra and current-power characteristics bear evidence of the high sensitivity and selectivity of the photodetectors in the UV region, which favor their application for the detection of weak radiation signals, including detection during day-time.

Advanced Inorganic Materials for Hard Magnetic Media

A review of magnetic materials used in modern hard magnetic media is presented. Advanced materials and technologies, along with conventional ones, are described. The capabilities and prospects of further development of data recording and storage systems are discussed.

A 128 × 128 pixel ultraviolet photodetector based on a diamond sensor

A new 128 × 128 pixel matrix photodetector with a semiconductor diamond sensor is designed, fabricated, and studied. A 128 × 128 pixel ultraviolet image is detected experimentally.

Diamond-based photosensitive matrix elements for the UV range

The design principles and the production technology for diamond-based photosensitive matrix devices operating in the UV range are considered. The spectral and I–V characteristics and the dark and leakage currents of linear (2 × 64) and matrix (64 × 64) photodetectors are measured at various applied voltages. The possibility of creating such structures with a relatively high sensitivity is demonstrated for the first time. It is shown that the surface leakage currents play the dominant role in limiting the photosensitivity of the structures under study. A significant spread of the dark current and the photocurrent of matrix photodetectors based on natural diamond is revealed. Such a spread is related to the defect-structure heterogeneity.

Promising CMOS ICs Based on Si/CaF2/Si Epitaxial Layers

It is shown that MBE-grown Si/CaF2/Si heterostructures are promising for SOI technology. On the basis of these heterostructures, test MIS/SOI structures were created. The mean electron mobility in the top silicon layer was found to be 450–600 cm2/ (V s). A test CMOS IC with a CoSi2gate and a CaF2gate dielectric was produced. The room-temperature ultimate speed of this structure was estimated (and measured) at a level of 1.5–2 GHz for a supply voltage of 3.0 V.

Problem of fabrication of diamond-based high-power microwave FETs

Numerical experiments are used to plan the development of diamond-based microwave FETs with an output power of 2.5 W per 1 mm of the gate width at a frequency of 15 GHz. A family of the I–V characteristics of the Schottky-barrier FET with gate length LG = 50 nm and width W = 1 mm is calculated. Bases on analogy with a TGF2023-20 GaN HEMT, the topology of the high-power diamond transistor (parallel cells with gate widths W = 1.2 mm and 24 elementary gates per cell) is constructed.

Bispectral diamond hybrid photodetectors

Original Russian Text

Switching effects in the films based on Ge2Sb2Te5

Experimental results on the switching effects related to the phase transitions in Ge2Sb2Te5 in the presence of external voltage or laser irradiation are presented. An electron model of the reversible switching is discussed.

Stability of magnetooptical disks under the action of external magnetic fields

The stability of data recorded on magnetooptical disks of different manufacturers is investigated under external magnetic fields oriented along the normal to the disk surface. The recorded data are found to be damaged under magnetic fields with intensities ranging from 300 to 350 kA/m. However, such disks can be reused for information recording. Under the action of magnetic fields with intensities more than 420 kA/m, information on disks is lost and they cannot be reused.

Magnetic Systems Based on Planar Solenoids for Devices Intended to Destruct Information on Magnetic Carriers

The magnetic systems based on planar solenoids, which are used in the implementation of devices of guaranteed and urgent destruction of data on magnetic carriers, are discussed. The magnetic fields of planar solenoids with different spiral wire windings are calculated. It is shown that selection of geometric parameters of a planar solenoid makes it possible to create the desired spatial configuration of a magnetic field, ensuring the field intensity required in magnetization of each domain of an information-carrying element.