Effect of In Mole Fraction on Gamma Ray Shielding Properties of InxAl1–xAs Material

Abstract The gamma-ray shielding performance of InxAl1–xAs with different In mole fractions was systematically investigated via the Phy-X/PSD. Key shielding parameters including mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), atomic cross-section (ACS), electronic cross-section (ECS), effective atomic number (Zeff), effective electron density (Neff), effective conductivity (Ceff), R-value, and equivalent atomic number (Zeq) were calculated over the energy range of 0.015–15 MeV. The results demonstrate that the MAC, LAC, ACS, ECS, Zeff, Ceff, and Zeq values increase with a rising In mole fraction, with In0.8Al0.2As exhibiting the highest values among the studied samples, alongside lower HVL, TVL, and MFP values. At equivalent photon energies, a linear correlation was observed between HVL, TVL, and MFP and the In mole fraction as x increased from 0.25 to 0.8. To quantify the composition-driven enhancement, a comprehensive shielding performance index (ICSP) was defined, and In0.8Al0.2As showed up to a 369% improvement at 0.1 MeV relative to In0.25Al0.75As.These findings suggest that increasing In content effectively enhances the gamma-ray attenuation capability of InAlAs materials. Furthermore, the observed linear relationships between shielding parameters and composition enable the prediction and optimization of shielding performance through compositional tuning, providing a theoretical foundation for the compositional design of III–V compound semiconductors in radiation shielding applications.