Screening (SbTe)1-xNMx Solid Solutions Towards to Phase-Change Memory Materials Applications: A High-Throughput Computational Study

Recently, chalcogenide phase-change materials have been widely applied in phase-change random access memory. However, the materials still have shortcomings of poor stability and low crystalline resistivity, causing high-power consumption, resistance drift, and short device life in phase-change random access memory. These do not meet the technical requirements and need to be modified. To improve Sb-Te systems alloy materials' properties and discover new phase-change materials, in this work, we construct 16 solid-solution systems based on SbTe (Sb1-xNMx)Te and Sb(Te1-xNMx) (NM = noble metals). We use a high-throughput computing method to calculate and analyze the underlying physical mechanism of solid-solution noble metal atoms' effects on improving the performance of phase-change materials. Based on the calculation results, we believe that the (Sb1-xNMx)Te solid solutions are more stable than Sb(Te1-xNMx). At the same time, the solid solution of the substituted Sb atom sites keeps the crystal structure symmetry improved structural stability. Furthermore, lone-pair electrons exist due to (Sb1-xNMx)Te keeping the SbTe's unique layer structure, which confers a higher activity of the surrounding atoms. This is an essential determinant for keeping the phase-change properties. On the other hand, (Sb1-xNMx)Te solid solutions increase the band gap, leading to increased resistivity. Considering the structural stability and electrical properties, we believe that the (Sb1-xRux) and (Sb1-xPdx)Te systems can create new phase-change materials. [GRAPHICS]

Automated summary

Chalcogenide phase-change materials are widely used in phase-change random access memory, but they still have issues of poor stability and low crystalline resistivity. In this study, by constructing 16 solid-solution systems based on SbTe, the researchers found that (Sb1-xNMx)Te solid solutions are more stable than Sb(Te1-xNMx) and can improve the phase-change properties. The (Sb1-xRux) and (Sb1-xPdx)Te systems show potential for creating new phase-change materials with improved structural stability and electrical properties.