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[Display omitted] Interfacial Phase Change Memory (iPCM) retrench unnecessary power consumption due to wasted heat generated during phase change by reducing unnecessary entropic loss. In this study, an advanced iPCM (GeTe/Ti-Sb 2 Te 3 Superlattice) is synthesized by doping Ti into Sb 2 Te 3. Structural analysis and density functional theory (DFT) calculations confirm that bonding distortion and structurally well-confined layers contribute to improve phase change properties in iPCM. Ti-Sb 2 Te 3 acts as an effective thermal barrier to localize the generated heat inside active region, which leads to reduction of switching energy. Since Ge-Te bonds adjacent to short and strong Ti-Te bonds are more elongated than the bonds near Sb-Te, it is easier for Ge atoms to break the bond with Te due to strengthened Peierls distortions (R long /R short) during phase change process. Properties of advanced iPCM (cycling endurance, write speed/energy) exceed previous records. Moreover, well-confined multi-level states are obtained with advanced iPCM, showing potential as a neuromorphic memory. Our work paves the way for designing superlattice based PCM by controlling confinement layers. [ABSTRACT FROM AUTHOR]

Via in situ transmission electron microscopy, we observed on nanoscale unconventional structural evolution during two-dimensional (2D) phase transitions in a Sb 2 Te 3 /TiTe 2 phase-change heterostructure (PCH), which reduces amorphous relxation and crystallization stochasiticity to facilitate rapid and reliable memory programming. [Display omitted] Phase-change heterostructure (PCH) holds great promise for overcoming the low-precision bottleneck that limits multibit storage and parallel computing in conventional phase-change random-access memory. However, the origin of high-accuracy control of electrical resistance achieved in programming PCH memory devices has yet to be established. Via in situ transmission electron microscopy, here we unveil the unusual microscopic processes during the order–disorder phase transitions driven by electrical pulse in a Sb 2 Te 3 /TiTe 2 PCH architecture. The template-modulated phase transition is confirmed to be two-dimensional (2D) in nature. The structural transformation path and dynamics in the confined Sb 2 Te 3 sublayers are found to be profoundly changed with respect to those in bulk monolithic Sb 2 Te 3 , leading to markedly suppressed amorphous relaxation and substantially reduced crystallization stochasticity, both highly desirable for swift and accurate device operations. Our atomic-scale observations provide direct evidence of, and much-needed insight into, the working mechanisms that may enable superior 2D phase-change electronic devices. [ABSTRACT FROM AUTHOR]