Function composites materials for shielding applications: Correlation between phase separation and attenuation properties

The problem of increasing reliability of semiconductor devices under extreme ionizing radiation (electrons, protons, gamma radiation etc.) is relevant. Uses of WCu composite materials with high density and reduced mass-dimension characteristics offer a very attractive alternative to lead protection due to more environmentally friendly composite. W85Cu15 and W75Cu25 composites were obtained by solid-phase synthesis. XRD data showed that the main lines of the WCu spectrum correspond to the body-centered cubic phase of tungsten-copper alloy and the face-centered cubic phase of copper. The W85Cu15 and W75Cu25 composites consist two main phases: W0,6Cu0,4 phase and Cu phase. This may be due to the alloy presence on the outer part of the tungsten grains, which was formed as a result of thermal annealing and copper diffusion during composite synthesis. The most intense peak (110) is maintained when the tungsten concentration changes. The peaks shift towards large angles with a tungsten concentration decreasing in the composite is observed. The intensity of copper peaks increases and a new low-intensity peak appears (220) with the copper concentration increasing in the composite. The shielding properties of the W85Cu15 composite with n- and p-MOS transistors under 1.6÷1.8 MeV electron radiation have been studied. It has been established that maximum shielding efficiency for p-MOS transistors (Ka = 143÷155) have shields with 1.2÷1.5 mm thickness. Shields provide the total absorbed dose reduction up to 6 times for outer space protons (energies from 0.04 to 500 MeV for the 60° orbital inclination and a circular orbit with a height of 300 km). •It has been shown that WCu composites consist three main phases (W,W0,6Cu0, 4 and Cu).•Isostructural W/W0,6Cu0,4 phases ratio critical determines shielding properties.•It has been demonstrated the optimal WCu thickness for best electron protection.•Shields based on W85Cu15 provide a reduction of the proton up to 6 times.