PRECISION CASTING INTO DISPOSABLE CERAMIC MOLD – A HIGH EFFICIENCY METHOD OF PRODUCTION OF CASTINGS OF IRREGULAR SHAPE

The article shows the advantages and disadvantages of precision casting into disposable ceramic molds. The high quality shaped castings produced by modernized ceramic molding process are proved the reliability and prospects of this advanced technology

РАЗЛИЧНЫЕ ТИПЫ СТРУКТУР АНТИПРОЖИГАЕМЫХ ПЕРЕМЫЧЕК ДЛЯ ПРОГРАММИРУЕМЫХ ПОЛЬЗОВАТЕЛЕМ ВЕНТИЛЬНЫХ МАТРИЦ И ПОСТОЯННЫХ ЗАПОМИНАЮЩИХ УСТРОЙСТВ

The use of anti-fuses as programmable elements is becoming popular in field programmable gate arrays and programmable read-only memories. The characteristics of various structures of anti-fuses and compromise between performance and reliability will be discussed in this paper.Использование антипрожигаемых перемычек в качестве программируемых элементов становится все более популярным в программируемых пользователем вентильных матрицах и программируемых постоянных запоминающих устройствах. В работе обсуждаются характеристики различных структур антипрожигаемых перемычек, а также компромисс между производительностью и надежностью

Carrier transport in porous-SiNic-Si nanostructures

In the present paper we have studied the peculiarities of carrier transport properties of nanoheterostructures containing silicon substrate covered with porous silicon layer, where pores were either filled or non-filled with ferromagnetic Ni clusters.We have carried out DC conductivity experiments as a function of temperature (ranging from 2 to 300 K) and porosity of porous silicon layer (between 30% and 70%). Presence of a surface layer with high resistance on the porous silicon top and its role in nanoheterostructure formation was revealed. It was shown that specific electrochemical kinetics of Ni deposition into porous silicon significantly influences resultant nanostructure resistance and high temperature conductance activation energy

Fabrication and simulation of silver nanostructures on different types of porous silicon for surface enhanced Raman spectroscopy

In this paper, we propose a systematic approach to controllably fabricate silver nanoparticles, dendrites and nanovoids on porous template based on silicon and two-step wet process. Geometry of metallic structures was managed by variation of dopant type of silicon, regimes of template formation and deposition of silver. General models of each structure were developed and studied for distribution and strength of electric field arising in them under 473, 633 and 785 nm laser excitation. Simulation results revealed reasons of variable activity of the fabricated structures in surface enhanced Raman spectroscopy, which allowed to define optimal conditions of analysis of target molecules

Кристаллическая и магнитная структуры твердых растворов на основе BiFeO3

The correlation between the multiphase state of the system and its magnetic properties was studied on Bi1–xEuxFeO3 ceramic samples in the range 0.12 ≤ x ≤ 0.18. The X-ray diffraction results indicate that, with an increase in the concentration of Eu ions, a structural transition from the rhombohedral (R3c) to nonpolar orthorhombic (Pnma) phase is observed through the partial formation of an antipolar orthorhombic structure (Pbam). The mixed phase state in the obtained compounds is observed in the range 0.12 ≤ x ≤ 0.16. Magnetic measurements in a strong magnetic field indicate a weak ferromagnetic interaction. The magnetic response in a strong field is explained by the location of the spins at the phase boundary, as well as by the presence of intrinsic antiferromagnetic spins.Исследование корреляции между многофазным состоянием системы и ее магнитными свойствами было проведено на керамических образцах Bi1-xEuxFeO3 с 0,12 ≤ x ≤ 0,18. Результаты рентгеновской дифракции свидетельствуют о том, что с увеличением концентрации ионов Eu наблюдается структурный переход от ромбоэдрической (R3c) к неполярной орторомбической (Pnma) фазе через частичное образование антиполярной орторомбической структуры (Pbam). Смешанное фазовое состояние в полученных соединениях наблюдается в интервале 0,12 ≤ x ≤ 0,16. Магнитные измерения в сильном магнитном поле указывают на слабое ферромагнитное взаимодействие. Магнитный отклик в сильном поле объясняется расположением спинов на фазовой границе, а также наличием собственных антиферромагнитных спинов

All silicon passive addressed micro LED displays with nano-porous Si/ITO-free nanomesh layers as light emitting pixels

In this paper we will concentrate on the usage of novel technologies and nanostructured materials to fabricate low cost high efficient micro LED displays with unique features. Possible areas of application will be discussed as well

Influence of Si conductivity type on immersion deposition of Cu films on porous Si

An immersion deposition of copper (Cu) on a porous silicon (PS) from an aqueous solution of the copper sulfate (CuSO4) and hydrofluoric acid (HF) has been performed. The PS based on n+- and p+-silicon (Si) wafers has been used to study the Cu deposition depending on the conductivity type of the initial Si substrate. The PS/n+-Si substrate has been found to allow the deposition of the nanostructured Cu films on the PS, while the PS/p+-Si has been shown to provide the formation of the porous Cu films by the complete substitution of the Si atoms in the PS with the Cu atoms

Various anti-fuse structures for field programmable gate arrays and programmable read-only memories

The use of anti-fuses as programmable elements is becoming popular in field programmable gate arrays and programmable read-only memories. The characteristics of various structures of anti-fuses and compromise between performance and reliability will be discussed in this paper

Fabrication and properties of porous silicon – iron magnetic nanocomposites

Porous silicon (PS)/Fe nanocomposites were fabricated by electrochemical deposition of Fe into pores of mesoporous silicon template under the stationary galvanostatic regime. Magnetic properties of PS/Fe nanocomposite were investigated by measuring the temperature dependence (77 – 700 K) of the specific magnetization (T) dependencies allowed us to determine the Curie temperature, Tc, which is very close to of the Curie temperature of the bulk Fe. A crystalline of the PS/Fe nanocomposites was studied by XRD. No peaks corresponded to Fe oxides are revealed on the XRD patterns