Cohesion properties of W/La2O3 interfaces from first principles calculation

First principles calculation reveals that the La-rich La2O3(0001) surface has much lower work function than the W(110) surface, which fundamentally improves the electron emission properties of W-La2O3 materials. Calculation also shows that the chemical potential of oxygen (μO) has an important effect on interface cohesion, i.e., the oxygen-rich and La-rich W(110)/La2O3(0001) interfaces are energetically more favorable with higher interface strength when −8.93 eV<μO≤ −4.89 eV and −10.79 eV≤μO≤ −8.93 eV, respectively. Moreover, it is found that the addition of La2O3 in W should lower the cohesion strength of W atoms, and the W/La2O3 interfaces or La2O3 particles would be the fracture positions in W-La2O3 materials. The bond analysis and electronic structures provide a deep understanding to various interface properties, and the calculated results are in excellent agreement with experimental observations.