Basic equations of the dynamical scattering theory in momentum space have been considered in the two-beam approximation for single crystals containing randomly distributed microdefects commensurable with extinction length. The amplitudes of coherent and diffusely scattered waves inside the crystal have been found by using the perturbation theory with average and fluctuating parts of crystal polarizability as small parameters. In the complex dispersion corrections to the wave vectors of coherent and diffuse waves, the imaginary parts of which describe the attenuation of these waves due to diffuse scattering, the dynamical effects in diffuse scattering and their dependences on the incidence angle have been taken into account. These corrections also take account of the influence of any multiple diffuse scattering processes. The coherent component of crystal reflectivity has been calculated in the approximation of semiinfinite crystal for an arbitrary diffraction geometry.Osnovnye uravneni¾ dinamiqeskoj teorii rasse¾ni¾ v impul#snom prostranstve rassmotreny v dvuhvolnovom pribliwenii dl¾ monokristallov, soderwa §ih sluqajno raspredelennye mikrodefekty s radiusami por¾dka +kstinkcionnoj dliny. Amplitudy kogerentnyh i diffuzno rasse¾nnyh voln vnutri kristalla najdeny s ispol#zovaniem teorii vozmu §enij so srednej i fluktuacionnoj qast¾mi pol¾rizuemosti krustalla v kaqestve malyh parametrov. V kompleksnyh dispersionnyh popravkah k volnovym vektoram kogerentnyh i diffuznyh voln, mnimye qasti kotoryh opisyvaˇt zatuhanie +tih voln iz-za diffiznogo rasse¾ni¾, uqteny dinamiqeskie +ffekty v diffuznom rasse¾nii i ih zavisimost# ot ugla padeni¾. *ti popravki uqityvaˇt takwe vli¾nie lˇbyh mnogokratnyh processov diffuznogo rasse¾ni¾. Kogerentna¾ komponenta otrawatel#noj sposobnosti kristalla vyqislena v pribliwenii polubeskoneqnogo kristalla dl¾ proizvol#noj geometrii difrakcii.
Dynamical wave fields formed in imperfect single crystals by diffusely scattered waves have been considered in the two-beam case of diffraction for the homogeneous distribution of microdefects with large sizes. Wave vectors of the constituent plane waves include the complex dispersion corrections accounting for multiple diffuse scattering processes. The corresponding dynamical diffuse scattering amplitudes and cross-sections in vacuum have been derived for both reflection and transmission directions. The diffuse component of crystal reflectivity has been calculated in the approximation of semiinfinite crystal and has been integrated over exit angles for two microdefect types: spherical clusters and prismatic dislocation loops. The obtained formula for the diffuse reflectivity has been analyzed and compared with the known kinematical one.Dinamiqeskie volnovye pol¾, obrazuemye v nesoverxennyh monokristallah diffuzno rasse¾nnymi volnami, rassmotreny v dvuhvolnovom sluqae difrakcii dl¾ odnorodnogo raspredeleni¾ mikrodefektov bol#xih razmerov. Volnovye vektory sostavl¾ˇ §ih ih ploskih voln soderwat kompleksnye dispersionnye popravki, uqityvaˇ §ie processy mnogokratnogo diffuznogo rasse¾ni¾. Sootvetstvuˇ §ie amplitudy i seqeni¾ dinamiqeskogo diffuznogo rasse¾ni¾ v vakuume vyvedeny dl¾ napravlenij otraweni¾ i prohowdeni¾. Diffuzna¾ komponenta otrawatel#noj sposobnosti kristalla vyqislena v pribliwenii polubeskoneqnogo kristalla i prointegrirovana po uglam vyhoda dl¾ mikrodefektov dvuh tipov: sferiqeskih klasterov i prizmatiqeskih dislokacionnyh petel#. Vypolnen analiz poluqennoj formuly dl¾ diffuznoj otrawatel#noj sposobnosti i provedeno ee sravnenie s izvestnym kinematiqeskim vyraweniem.
The dynamical theory, which describes both diffraction profiles and reciprocal space maps measured from imperfect crystals with account for instrumental factors of triple‐crystal diffractometer (TCD), has been developed for adequate quantitative characterization of microdefects. Analytical expressions for coherent and diffuse scattering (DS) intensities measured by TCD in the Bragg diffraction geometry have been derived by using the generalized statistical dynamical theory of X‐ray scattering in real single crystals with randomly distributed defects. The DS intensity distributions from single crystals containing clusters and dislocation loops have been described by explicit analytical expressions. Particularly, these expressions take into account anisotropy of displacement fields around defects with discrete orientations. Characteristics of microdefect structures in silicon single crystals grown by Czochralsky‐ and float‐zone methods have been determined by analyzing the measured TCD profiles and reciprocal space maps. The sensitivities of reciprocal space maps and diffraction profiles to defect characteristics have been compared.
В работе исследованы энергетические спектры электронов и предсказаны диаграммы магнитных фазовых состояний неупорядоченных бинарных ОЦК-сплавов замещения с различными значениями параметра рассеяния электронов на атомах обоих компонентов. Для описания таких сплавов предложена однозонная модель сильной связи, учитывающая электрон-электронные взаимодействия в приближении коррелированного случай-ного поля. Показано, что тип магнитного порядка сплавов определяется как энергетическими параметрами кулоновского отталкивания электро-нов с противоположными спинами на одном узле и средней электронной концентрацией, так и величиной атомного потенциала рассеяния. В от-личие от однокомпонентных систем в исследованных сплавах антиферро-магнитное упорядочение имеет пороговый характер, то есть для всех воз-можных значений средней электронной концентрации оно не может устанавливаться при сколь угодно малых значениях потенциала куло-новского отталкивания электронов на одном узле. В роботі досліджено енергетичні спектри електронів і передбачено діаг-рами магнітних фазових станів невпорядкованих бінарних ОЦК-стопів заміщення з різними значеннями параметра розсіяння електронів на ато-мах обох компонентів. Для опису таких стопів запропоновано однозонну модель сильного зв'язку, що враховує електрон-електронні взаємодії в наближенні корельованого випадкового поля. Показано, що тип магніт-ного порядку стопів визначається як енергетичними параметрами Куло-нового відштовхування електронів з протилежними спінами на одному вузлі і середньою електронною концентрацією, так і величиною атомного Металлофиз. новейшие технол. / Metallofiz. Noveishie Tekhnol. 2014, т. 36, № 5, сс. 575-588 Оттиски доступны непосредственно от издателя Фотокопирование разрешено только в соответствии с лицензией 2014 ИМФ (Институт металлофизики им. Г. В. Курдюмова НАН Украины) Напечатано в Украине.
The quantitative characterization of complex microdefect structures in silicon crystals grown by Czochralski method and irradiated with various doses of high-energy electrons (18 MeV) has been performed by methods of the highresolution X-ray diffraction. The concentrations and average sizes of dislocation loops and oxygen precipitates have been determined by using the combined treatment of reciprocal space maps and rocking curves based on the analytical formulas of the statistical dynamical theory of X-ray diffraction by imperfect crystals with randomly distributed microdefects of several types.
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