Магнітна сприйнятливість ниткоподібних кристалів Si0,97Ge0,03 опромінених протонами

The article deals with the filamentous Si0,97Ge0,03 crystals with transverse dimensions of 40 ± 2 μm grown by the method of chemical transport reactions in the closed bromide system using gold as a growth initiator. The focus of research was the influence of proton irradiation with doses up to 1∙1017 p+/cm-2 and the following thermal treatments at temperatures of 200 - 500°C on the magnetic susceptibility of these crystals. The dependence of the magnetic susceptibility on the intensity of the magnetic field of the proton irradiated filamentous Si0,97Ge0,03 crystals is described within the framework of the Langevin atom paramagnetism model and explained by the formation of defects of the vacancy type. The revealed increase in the radiation stability of Si0,97Ge0,03 crystals followed the combined effect of radiation and subsequent thermal treatments.Методом хімічних транспортних реакцій в закритій бромідній системі, з використанням золота в якості ініціатора росту, вирощено ниткоподібні кристали Si0,97Ge0,03 поперечними розмірами 40 ± 2 мкм. Досліджено вплив протонного опромінення дозами до 1∙1017 p+/cm-2 та наступних термічних обробок за температур 200 – 500 оС на магнітну сприйнятливість цих кристалів. Залежності магнітної сприйнятливості від напруженості магнітного поля ниткоподібних кристалів Si0,97Ge0,03, опромінених протонами, описано в рамках моделі ланжевенівського парамагнетизму атомів та пояснено  утворенням дефектів вакансійного типу. Виявлено підвищення радіаційної стійкості кристалів Si0,97Ge0,03 після комбінованої дії опромінення та наступних термічних обробок

Structure and magnetic properties of Si<sun>0.97</sub>Ge_0.03 whiskers

By the method of chemical transport reactions in the closed halogen system Si-Au-Pt-B-Br, whiskers Si&lt;sub&gt;1-x&lt;/sub&gt;Ge&lt;sub&gt;x&lt;/sub&gt; x = 0.01-0.08 of transverse dimensions 0.1-100 μm were grown. Structural and magnetic properties of the obtained crystals are investigated. The method of scanning electron microscopy showeds that on the surface of needle-like crystals, with transverse dimensions of 50-80 microns, a porous shell with a thickness of 50-60 nm is present. From the analysis of the energy spectra of X-rays, it was found that the surface shell contains significant concentration atoms of oxygen and of carbon. In turn, oxygen and carbon peaks were not detected on the inner layers of samples. It has been established that the chemical etching of the surface layer of crystals leads to the improvement of their structural and magnetic properties. Key words: whiskers of silicon-germanium, electron microscopy, X-ray spectrum, magnetic susceptibility.</p

High-speed low-power and board-mountable optical transceivers for scalable &amp; energy efficient advanced on-board digital processors

We present the development and verification testing of a high speed multimode, multicore transceiver technology for intra-satellite optical interconnects. We report the fabrication and functional testing of opto-parts including 25 Gb/s 850 nm VCSEL/PD as well as the verification testing of the VCSELs against radiation and lifetime performance. In addition we report the development and evaluation testing of a multi-core cable assembly that was fabricated and mated with MiniAVIM multi-core connectors to develop hi-rel multi-core optical patchcords for pigtailing the transceiver modules. The fiber optic, electronic and opto-parts were used to assemble the first ever fully packaged and pigtailed, six-core optical transceiver prototype module that operates at 25 Gb/s channel bit rate at an energy consumption of ∠4.5 mW/Gb/s