Effect of the Synthesis Conditions and Microstructure for Highly Effective Electron Shields Production Based on Bi Coatings

Abstract

Microelectronic products are very sensitive to ionizing radiation (electrons, protons, heavy charged particles, X-ray, and γ radiation). Lead is the commonly used material for radiation protection. Bismuth deposition has become an interesting subject for the electrochemical community because of bismuth's unique electrical, physical, and chemical properties. There is a limited number of authors dealing with deposition of continuous bismuth films onto metallic substrates by electrodeposition method. The conditions of Bi electrochemical deposition and the structure of Bi coatings were examined. X-ray diffraction patterns for all samples were indexed to rhombohedral Bi. Coatings with a signified texture (012) are formed in electrolyte without additives. With gelatin the growth texture changes, and the most intense reflex becomes (110). It was found that increasing gelatin concentration from 0.1 to 0.5 g/L leads to Bi microstructural refinement from 4−20 μm, to from 50 nm to 2 μm, respectively. The protection efficiency of Bi-based shields under 1.6−1.8 MeV electron radiation energy was measured. The electron beam attenuation efficiency was estimated by the changing of current−voltage characteristics of semiconductor test structures which were located behind the shields and without them. It has been determined that optimal protection effectiveness and mass-dimensional parameters are enabled by Bi shields with 2 g/cm 2 reduced thickness and 156 attenuation coefficient.

Early-Stage Growth Mechanism and Synthesis Conditions-Dependent Morphology of Nanocrystalline Bi Films Electrodeposited from Perchlorate Electrolyte

“…This tendency is clearly visible in Figure 6 inserts, which present the porosity contrast images. Such a closely-packed Bi microstructure contributes to the creation of materials that can be widely used in the fields where a high level of density (low porosity) is important [18,20,21,23].…”

“…Bi-based sensitive radiation detectors, such as microcalorimeters demonstrate good X-ray absorption because of Bi's large atomic number and very low heat capacity [5,[18][19][20][21]. Uses of Bi-based composites and coatings offer a very applicable alternative to the lead protection against proton radiation due to much more environmentally friendly Bi [22,23]. Bi 2 O 3 -glasses showed high gamma radiation effectiveness [24], and textiles with filled Bi 2 O 3 particles are applied in the manufacture of overalls for medical personnel working on gamma-ray systems [25].…”

“…Many authors have focused on the Bi deposition onto noble metals (evaporated Au and polycrystalline Cu) and non-metallic substrates, such as semiconductors [41,42] and glassy carbon [43]. However, the number of authors who produce bismuth films onto metallic substrates is very limited [23,44,45]. Many previous studies have been dedicated to Bi films electrodeposition from lactate, tartrate, silicate, nitrate, citric, hydrochloric, stearic, sulfate, and pyrophosphate electrolytes [13,27,32,41,[46][47][48][49][50].…”

“…This electrolyte has several advantages: Homogeneous and dense coatings obtaining, high deposition rates, and it also approximates 100% current efficiency. Thick coating obtaining is one of the main tasks in the radiation protective shields manufacturing, so the use of the electrolyte, which allows achieving high electrodeposition rates, is very relevant [22,23]. To maximize the protective efficiency against various ionizing radiations is essential for semiconductor shielding applications as well as to get a deeper understanding of the Bi growth controllability [53,54].…”

Electrochemical Behaviour of Ti/Al2O3/Ni Nanocomposite Material in Artificial Physiological Solution: Prospects for Biomedical Application

“…After the exposure to the tumor, the magnetic nanostructures are deleted from the blood system by an external magnetic field [4]. Nanocomposite materials are widely used in the field of different biomedical applications such as developing of materials to replace/regenerate tissues starting from tissue engineering with mesenchymal stem cells (MSCs) and biomimetic scaffolds [10], bone therapeutic applications [11][12][13], especially in regards to pathological fractures/injuries such as the one derived from osteoporosis [14]. The role of inflammatory conditions in rehabilitation with biomaterials should be noted, as inflammatory phenomena may trigger the oxidative stress that would take advantage of perioperatory therapy [15].…”