A selected area electron diffraction and crossectional TEM image of as-deposited and 350 ℃ annealed NbTe 4 thin films. "With NbTe 4's low melting point, high crystallization temperature, and excellent switching performances, it is positioned as the ideal material to address some of the current challenges face by current PCMs."ĭetails of the group's discovery were published in the journal Advanced Materials on June 20, 2023. "We have opened up new possibilities for developing high-performance phase change memories," adds Shuang. Additionally, NbTe 4 demonstrated a fast-switching speed of approximately 30 nanoseconds, further highlighting its potential as a next-generation phase change memory.
The estimated 10-year data retention temperature was found to be as high as 135 ✬ - better than the 85 ✬ of GST - suggesting an excellent thermal stability and the possibility of NbTe 4 to be used in high-temperature environments such as in the automotive industry. It exhibited a significant reduction in operation energy compared to conventional phase-change memory compounds. ©Yi Shuang et al.Īfter fabricating the NbTe 4s, the researchers then evaluated its switching performance. A comparison of T c (crystallization temperature) and T m (melting point) values of various 2D TM chalcogenides The T c and T m values of NbTe 4 were defined by the onset temperature of crystallization and melting peaks in this study. This unique combination offers reduced reset energies and improved thermal stability at the amorphous phase. Unlike conventional amorphous-crystalline PCMs, such as Ge 2Sb 2Te 5 (GST), NbTe 4 demonstrates both a low melting point and a high crystallization temperature. "Our deposited NbTe 4 films were initially amorphous, but could be crystallized to a 2D layered crystalline phase by annealing at temperatures above 272 ✬." "Sputtering is a widely used technique that involves depositing thin films of a material onto a substrate, enabling precise control over film thickness and composition," explains Yi Shuang, assistant professor at Tohoku University's Advanced Institute for Materials Research and co-author of the paper. Using this technique, they fabricated and identified an exceptionally promising materialーniobium telluride (NbTe 4)ーthat exhibits an ultra-low melting point of approximately 447 ✬ (onset temperature), setting it apart from other TMDs. Now, a group of researchers from Tohoku University has highlighted the potential use of sputtering to fabricate large-area 2D vdW tetra-chalcogenides. In recent years, two-dimensional (2D) Van Der Waals (vdW) transition metal di-chalcogenides have emerged as a promising PCM for usage in phase change memory. But still, the complex switching mechanism and intricate fabrication methods associated with these materials have posed challenges for mass production.
Whilst this field is in its infancy, phase change memory could potentially revolutionize data storage because of its high storage density, and faster read and write capabilities. This change produces a reversible electrical property which can be engineered to store and retrieve data. Phase change memory is a type of nonvolatile memory that harnesses a phase change material's (PCM) ability to shift from an amorphous state, i.e., where atoms are disorganized, to a crystalline state, i.e., where atoms are tightly packed close together.
0 kommentar(er)
