Titanium-induced structure modification for thermal stability enhancement of a GeTeTi phase change material

Phase change materials rule the basic scientific issues in the research of phase change memory. As an important member in the phase change material system, GeTe is competitive for both technological applications and fundamental studies. However, its relatively poor thermal stability in the amorphous state and serious grain clustering need to be overcome for the application of GeTe. Here we propose Ge-Te-Ti (GTT) as a novel phase change material. For GTT, just with a small Ti fraction, the temperature for 10 year's data retention reaches 175 degrees C, and its grain size decreases one order of magnitude. Results of Raman scatting measurements indicate that the basic structure unit distribution of GTT deviates from the normal distribution to the Ge-rich direction with the Ti fraction increasing. The Ti-induced amorphous structure adjustment in GTT is the physical origin for the thermal stability enhancement, which makes GTT more extensively applicable in high temperature fields through the appropriate disordering adjustment.