Structural transformation in C/Si multilayer after annealing

Amorphous C/Si multilayers were prepared by DC magnetron sputtering technique and investigated by transmission electron microscopy and low-angle x-ray diffraction methods after annealing at 650 and 950 °C. The amorphous interlayers of 0.5 − 0.6 nm thick were found at C/Si and Si/C interfaces being of different density and composition. Amorphous structure of the multilayer is stable up to 950 °C when crystallization of α-SiC occurs and voids form in α-Si layer.Изготовленные методом прямоточного магнетронного распыления аморфные многослойные композиции C/Si были исследованы методами просвечивающей электронной микроскопии и малоугловой рентгеновской дифракции после отжигов при температуре 650 и 950 °C. На границах раздела C/Si и Si/C обнаружены аморфные перемешанные зоны толщиной 0.5 – 0.6 нм c различными плотностью и составом. Аморфная структура многослойной композиции стабильна вплоть до 950 °C, когда наблюдается формирование пор в слоях α-Si и кристаллизация α-Si

Soft X-ray imaging of thick carbon-based materials using the normal incidence multilayer optics

The high transparency of carbon-containing materials in the spectral region of “carbon window” (∼4.5–5 nm) introduces new opportunities for various soft X-ray microscopy applications. The development of efficient multilayer coated X-ray optics operating at the wavelengths of about 4.5nm has stimulated a series of our imaging experiments to study thick biological and synthetic objects. Our experimental set-up consisted of a laser plasma X-ray source generated with the 2nd harmonics of Nd–glass laser, scandium-based thin-film filters, Co/C multilayer mirror and X-ray film UF-4. All soft X-ray images were produced with a single nanosecond exposure and demonstrated appropriate absorption contrast and detector-limited spatial resolution. A special attention was paid to the 3D imaging of thick low-density foam materials to be used in design of laser fusion target