In this paper, Ni-doped Ge2Sb2Te5 (GST) was investigated for high speed phase change memory applications. Compared with GST, Ni0.3Ge2.8Sb2.2Te4.2 film exhibits a higher crystallization temperature (similar to 217 degrees C) and a better data retention ability (similar to 135 degrees C for 10 years). A reversible switching between set and reset can be realized by an electric pulse as short as 6-ns for Ni0.3Ge2.8Sb2.2Te4.7 based phase change memory. Furthermore, Ni0.3Ge2.8Sb2.2Te4.7 based cell shows good endurance up to 1.5 x 10(4) SET RESET cycles during endurance test. (C) 2015 Elsevier Ltd. All rights reserved.