Yong-Jie Hu¹, Ge Zhao², Baiyu Zhang³, Chaoming Yang¹, Xiaofeng Qian³, Liang Qi¹; ¹University of Michigan, ²The Pennsylvania State University , ³Texas A&M University

We discovered a universal correlation between two electronic descriptors and the solute-defect interaction energies in binary alloys of bcc refractory metals with transition-metal substitutional solutes. One electronic descriptor is the bimodality of the d-orbital local density of states for a matrix atom at the substitutional site, and the other is related to the hybridization strength between the valance sp- and d-bands for the same matrix atom. To test the predictive capabilities of the correlation model, substantial first-principles calculations were performed to calculate the solute segregation energies at complex high-index grain boundary (GB) structures in W and Ta. By comparing with direct first-principles calculations, our model shows excellent performance on the predictions of segregation energies and the overall temperature-dependent GB segregation concentrations for different matrix-solute element pairs. This newly discovered correlation model could be used as a screening tool to study the solute segregation in grain boundaries and other crystalline defects.