Electron work function–a promising guiding parameter for material design

Abstract

Using nickel added X70 steel as a sample material, we demonstrate that electron work function (EWF), which largely reflects the electron behavior of materials, could be used as a guide parameter for material modification or design. Adding Ni having a higher electron work function to X70 steel brings more “free” electrons to the steel, leading to increased overall work function, accompanied with enhanced e−–nuclei interactions or higher atomic bond strength. Young’s modulus and hardness increase correspondingly. However, the free electron density and work function decrease as the Ni content is continuously increased, accompanied with the formation of a second phase, FeNi3, which is softer with a lower work function. The decrease in the overall work function corresponds to deterioration of the mechanical strength of the steel. It is expected that EWF, a simple but fundamental parameter, may lead to new methodologies or supplementary approaches for metallic materials design or tailoring on a feasible electronic base.

Structural, Electrical, and Optical Effects of Metal Doping on ZnO Thin Films

“…As an additional remarkable finding of this study, Ti, W, and Zr doped films exhibit a higher Volta potential and therefore a higher work function than pristine ZnO. Materials with higher work functions are thought to be more stable and have an increased hardness than the undoped ones . These material combinations may be interesting in research for high strength materials.…”

Tunable structural and electrical properties of zigzag CdS nanotubes: A density functional study

“…Work function may affect band alignment and transport properties at a junction, device integration. Furthermore, from the knowledge of work function, one may get an insight into the mechanical properties of a material . Therefore, work function is a promising parameter for determining material properties and thus for designing new devices.…”

Hardening tungsten carbide by alloying elements with high work function

“…As for the (0001) W-terminated plane, this plane only has metal atoms without carbon, thus the work function of this plane is similar to those of alloy systems. The work function of a single phase alloy equals the average of those of the components approximately (Lu et al, 2016;Rothschild & Eizenberg, 2010). Thus, alloying elements with high work functions may increase the overall work function of (0001) Wterminated plane, while alloying elements with low work functions may decrease its overall work function.…”

“…The work function has been correlated to the bond energy and some bond strength related properties using the Lennard-Jones potential as a bridge (Lu & Li, 2014). Therefore, the intrinsic mechanical properties of materials are dependent on work function and the properties of materials could be optimized by tuning the work function (Hua & Li, 2011;Lu et al, 2016Lu et al, , 2018. However, few studies focus on improving the hardness of refractory metal carbides by adjusting their work functions, although an abundant database of refractory and transition metal carbides work function has been established experimentally and theoretically (Yoshitake, 2014;Fujii et al, 2006).…”