The thermal conductivity of ZrCo alloy under doping effect: First principles study

ZrCo alloy is considered to be one of the most promising materials for hydrogen isotope treatment in the International Thermonuclear Experimental Reactor (ITER) due to its significant advantages in dehydrogenation kinetics, thermodynamics, and safety. The heating during the dehydrogenation process, on the other hand, can easily induce H2 to penetrate the surrounding environment, resulting in hydrogen embrittlement and threatening structural safety. The system's temperature regulation is very critical. The electronic thermal conductivity of ZrCo was computed using the BoltzTraP2 program and the constant relaxation time approximation based on density functional theory (DFT). The phonon thermal conductivity is calculated by lattice dynamics using the finite displacement supercell method. Between 300 K and 800 K, the thermal conductivity and electrical conductivity of ZrCo alloy were effectively predicted for the first time. The effects of Ti and V doping on ZrCo alloy thermal conductivity were investigated. The results show that when temperature rises, phonon-electron and phonon-phonon scattering will be enhanced. Resistance and thermal resistance will also rise, while conductivity and thermal conductivity would decrease. The doping of Ti and V elements will reduce the electronic thermal conductivity of the system. Different concentrations of doping bring different degrees of defects, affecting the average electron-phonon free path, and thereby reducing thermal conductivity.