Threshold Irradiation Dose for Amorphization of Silicon Carbide
Threshold Irradiation Dose for Amorphization of Silicon Carbide

Author:

Publisher:

Published: 1997

Total Pages: 13

ISBN-13:

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The amorphization of silicon carbide due to ion and electron irradiation is reviewed with emphasis on the temperature-dependent critical dose for amorphization. The effect of ion mass and energy on the threshold dose for amorphization is summarized, showing only a weak dependence near room temperature. Results are presented for 0.56 MeV silicon ions implanted into single crystal 6H-SiC as a function of temperature and ion dose. From this, the critical dose for amorphization is found as a function of temperature at depths well separated from the implanted ion region. Results are compared with published data generated using electrons and xenon ions as the irradiating species. High resolution TEM analysis is presented for the Si ion series showing the evolution of elongated amorphous islands oriented such that their major axis is parallel to the free surface. This suggests that surface or strain effects may be influencing the apparent amorphization threshold. Finally, a model for the temperature threshold for amorphization is described using the Si ion irradiation flux and the fitted interstitial migration energy which was found to be (approximately)0.56eV. This model successfully explains the difference in the temperature dependent amorphization behavior of SiC irradiated with 0.56 MeV Si at 1 x 10−3 dpa/s and with fission neutrons irradiated at 1 x 10−6 dpa/s irradiated to 15 dpa in the temperature range of (approximately)340"10K.

Microstructure Evolution During Irradiation: Volume 439
Microstructure Evolution During Irradiation: Volume 439

Author: Ian M. Robertson

Publisher:

Published: 1997-06-25

Total Pages: 770

ISBN-13:

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This book from MRS discusses the evolution of a material's microstructure as a result of its interaction with energetic particles such as ions, neutrons or electrons. The book is inter-disciplinary and emphasizes all classes of materials including metals, intermetallic compounds, ceramics, polymers, superconductors, semiconductors and insulators. A strong focus is placed on experimental techniques for measuring and quantifying damage and microstructure changes, and on computer simulation techniques for predicting and understanding this phenomena. Topics include: ion-implantation damage in semiconductors; radiation damage in metals; radiation damage in ceramics; radiation effects in polymers and beam-induced effects.

Comprehensive Nuclear Materials
Comprehensive Nuclear Materials

Author:

Publisher: Elsevier

Published: 2020-07-22

Total Pages: 4871

ISBN-13: 0081028660

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Materials in a nuclear environment are exposed to extreme conditions of radiation, temperature and/or corrosion, and in many cases the combination of these makes the material behavior very different from conventional materials. This is evident for the four major technological challenges the nuclear technology domain is facing currently: (i) long-term operation of existing Generation II nuclear power plants, (ii) the design of the next generation reactors (Generation IV), (iii) the construction of the ITER fusion reactor in Cadarache (France), (iv) and the intermediate and final disposal of nuclear waste. In order to address these challenges, engineers and designers need to know the properties of a wide variety of materials under these conditions and to understand the underlying processes affecting changes in their behavior, in order to assess their performance and to determine the limits of operation. Comprehensive Nuclear Materials, Second Edition, Seven Volume Set provides broad ranging, validated summaries of all the major topics in the field of nuclear material research for fission as well as fusion reactor systems. Attention is given to the fundamental scientific aspects of nuclear materials: fuel and structural materials for fission reactors, waste materials, and materials for fusion reactors. The articles are written at a level that allows undergraduate students to understand the material, while providing active researchers with a ready reference resource of information. Most of the chapters from the first Edition have been revised and updated and a significant number of new topics are covered in completely new material. During the ten years between the two editions, the challenge for applications of nuclear materials has been significantly impacted by world events, public awareness, and technological innovation. Materials play a key role as enablers of new technologies, and we trust that this new edition of Comprehensive Nuclear Materials has captured the key recent developments. Critically reviews the major classes and functions of materials, supporting the selection, assessment, validation and engineering of materials in extreme nuclear environments Comprehensive resource for up-to-date and authoritative information which is not always available elsewhere, even in journals Provides an in-depth treatment of materials modeling and simulation, with a specific focus on nuclear issues Serves as an excellent entry point for students and researchers new to the field

Silicon Carbide Amorphization by Electron Irradiation
Silicon Carbide Amorphization by Electron Irradiation

Author:

Publisher:

Published: 2001

Total Pages:

ISBN-13:

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Observations made more than ten years ago showed that SiC could be made amorphous at cryogenic temperatures by in-situ 300kV electron irradiation. However, high voltage electron microscope (HVEM) results indicate a threshold voltage of 725 kV for amorphization of SiC at 140 K. In addition, a recent review exposes the considerable uncertainty in the literature regarding displacement energies for SiC. Therefore, further experiments have been performed in a Philips CM30 (LaB[sub 6] cathode) with a Gatan double-tilt cooling holder in an attempt to determine the threshold voltage for amorphization at[approximately] 140 K. Sintered[alpha]-SiC (defected 6H polytype), beam direction B=11[bar 2]0, and probes containing[approximately] 75 nA in[approximately] 0.5[micro]m, were used. Amorphization occurred in

Radiation Effects in Silicon Carbide
Radiation Effects in Silicon Carbide

Author: A.A. Lebedev

Publisher: Materials Research Forum LLC

Published: 2017

Total Pages: 172

ISBN-13: 1945291117

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The book reviews the most interesting research concerning the radiation defects formed in 6H-, 4H-, and 3C-SiC under irradiation with electrons, neutrons, and some kinds of ions. The electrical parameters that make SiC a promising material for applications in modern electronics are discussed in detail. Specific features of the crystal structure of SiC are considered. It is shown that, when wide-bandgap semiconductors are studied, it is necessary to take into account the temperature dependence of the carrier removal rate, which is a standard parameter for determining the radiation hardness of semiconductors. The carrier removal rate values obtained by irradiation of various SiC polytypes with n- and p-type conductivity are analyzed in relation to the type and energy of the irradiating particles. The influence exerted by the energy of charged particles on how radiation defects are formed and conductivity is compensated in semiconductors under irradiation is analyzed. Furthermore, the possibility to produce controlled transformation of silicon carbide polytype is considered. The involvement of radiation defects in radiative and nonradiative recombination processes in SiC is analyzed. Data are also presented regarding the degradation of particular SiC electronic devices under the influence of radiation and a conclusion is made regarding the radiation resistance of SiC. Lastly, the radiation hardness of devices based on silicon and silicon carbide are compared.

Amorphous and Crystalline Silicon Carbide IV
Amorphous and Crystalline Silicon Carbide IV

Author: Cary Y. Yang

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 439

ISBN-13: 3642848044

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Silicon carbide and other group IV-IV materials in their amorphous, microcrystalline, and crystalline forms have a wide variety of applications.The contributions to this volume report recent developments and trends in the field. The purpose is to make available the current state of understanding of the materials and their potential applications. Eachcontribution focuses on a particular topic, such as preparation methods, characterization, and models explaining experimental findings. The volume also contains the latest results in the exciting field of SiGe/Si heterojunction bipolar transistors. The reader will find this book valuable as a reference source, an up-to-date and in-depth overview of this field, and, most importantly, as a window into the immense range of reading potential applications of silicon carbide. It is essential for scientists, engineers and students interested in electronic materials, high-speed heterojunction devices, and high-temperature optoelectronics.

The Effect of Grain Size on the Radiation Response of Silicon Carbide and Its Dependence on Irradiation Species and Temperature
The Effect of Grain Size on the Radiation Response of Silicon Carbide and Its Dependence on Irradiation Species and Temperature

Author:

Publisher:

Published: 2014

Total Pages: 0

ISBN-13:

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In recent years the push for green energy sources has intensified, and as part of that effort accident tolerant and more efficient nuclear reactors have been designed. These reactors demand exceptional material performance, as they call for higher temperatures and doses. Silicon carbide (SiC) is a strong candidate material for many of these designs due to its low neutron cross-section, chemical stability, and high temperature resistance. The possibility of improving the radiation resistance of SiC by reducing the grain size (thus increasing the sink density) is explored in this work. In-situ electron irradiation and Kr ion irradiation was utilized to explore the radiation resistance of nanocrystalline SiC (nc-SiC), SiC nanopowders, and microcrystalline SiC. Electron irradiation simplifies the experimental results, as only isolated Frenkel pairs are produced so any observed differences are simply due to point defect interactions with the original microstructure. Kr ion irradiation simulates neutron damage, as large radiation cascades with a high concentration of point defects are produced. Kr irradiation studies found that radiation resistance decreased with particle size reduction and grain refinement (comparing nc-SiC and microcrystalline SiC). This suggests that an interface-dependent amorphization mechanism is active in SiC, suggested to be interstitial starvation. However, under electron irradiation it was found that nc-SiC had improved radiation resistance compared to single crystal SiC. This was found to be due to several factors including increased sink density and strength and the presence of stacking faults. The stacking faults were found to improve radiation response by lowering critical energy barriers. The change in radiation response between the electron and Kr ion irradiations is hypothesized to be due to either the change in ion type (potential change in amorphization mechanism) or a change in temperature (at the higher temperatures of the Kr ion irradiation, critical energy barriers can be overcome without the assistance of stacking faults). The dependence of the radiation response of SiC on grain size is not as straight forward as initially presumed. The stacking faults present in many nc-SiC materials boost radiation resistance, but an increased number of interfaces may lead to a reduction in radiation response.