Article
Chemistry, Multidisciplinary
Cheng Liu, Yonghui Zheng, Tianjiao Xin, Yunzhe Zheng, Rui Wang, Yan Cheng
Summary: This study found that the first resistance dropping in the GST film is related to the increase of carrier concentration, and the atomic bonding environment changes significantly during the crystallization process. The second resistance dropping is related to the increase of carrier mobility. Additionally, during the cubic to the hexagonal phase transition, the nanograins grow significantly, reducing the carrier scattering effect. This study lays the foundation for precise control of the storage states of GST-based PCRAM devices.
Article
Chemistry, Physical
Xiaotian Zeng, Xiaoqin Zhu, Yifeng Hu
Summary: We report a [C(5 nm)/Sb2Te3(12 nm)]5 phase-change heterostructure film with multilevel phase change properties and low resistance drift. The addition of carbon broke the Sb2Te3 bond and formed new C-Sb and C-Te bonds. The reliability of the phase-change heterostructure was confirmed using transmission electron microscopy. The amorphous resistance drift index of the C/Sb2Te3 film was effectively reduced, possibly due to structure relaxation. PCM devices based on C/Sb2Te3 phase-change heterostructure films also demonstrated the potential for multilevel storage. This research provides a new method for achieving multilevel phase-change memories with low resistance drift.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Physics, Applied
Qinshu Li, Or Levit, Eilam Yalon, Bo Sun
Summary: The thermal conductivity of amorphous, cubic, and hexagonal Ge2Sb2Te5 has been measured using time-domain thermoreflectance. The results show different thermal conductivities for each phase, with the hexagonal phase having the highest value. These findings are important for improving the thermal design of phase change memory devices and achieving more energy-efficient non-volatile memory.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Bin Chen, Xue-Peng Wang, Fangying Jiao, Long Ning, Jiaen Huang, Jiatao Xie, Shengbai Zhang, Xian-Bin Li, Feng Rao
Summary: This study shows that by simplifying the composition and miniaturizing the dimensions of traditional GeSbTe-like phase-change materials (PCMs), resistance drift in PCRAM devices can be effectively suppressed. It is demonstrated that a thin Sb film, with an optimal thickness of only 4 nm, enables precise multilevel programming with ultralow resistance drift coefficients. This advancement is achieved through the slightly changed Peierls distortion in Sb and the less-distorted atomic configurations across the Sb/SiO2 interfaces.
Article
Chemistry, Multidisciplinary
Akash Singh, Yongshin Kim, Reece Henry, Harald Ade, David B. Mitzi
Summary: This study reports the glass formation and kinetic properties of low-melting-temperature 1-MeHa(2)PbI(4) perovskite. The slight loss of organic and hydrogen iodide components helps stabilize the glassy state, and the fast crystal growth rate shows potential for extended applications.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Ning Song, Shaopeng Chen, Xiaowei Fan, Yuhui Tan, Yunzhi Tang, Lijuan Wang, Juan Liao, Zhen Sun
Summary: Zero-dimensional perovskites have attracted extensive attention recently due to their unique structural properties. In this study, an organic-inorganic hybrid perovskite compound with excellent reversible phase transition and dielectric switching properties was reported. It was found that the introduction of fluorine atoms reduced the symmetry of the structure, resulting in a narrow bandgap and distinct dielectric anomalies. UV-vis absorption spectra and density-functional theory calculations confirmed the bandgap, revealing the main contribution of the inorganic [SbBr6] octahedral framework. This work highlights the importance of halogen substitution in the synthesis of novel organic-inorganic hybrid perovskite phase-transition materials.
Article
Materials Science, Multidisciplinary
V. Shobin Vijay, Rojin Varghese, A. Sakunthala, S. Rajesh, B. Vidhya
Summary: Vanadium oxide thin films were deposited on stainless steel substrates at different temperatures using pulsed laser deposition technique. The effect of post-annealing on the crystallization of V2O5 film was studied, showing a positive impact on crystallization. The structural and morphological properties were analyzed using XRD, Raman, and SEM, revealing changes in phase orientations and tunable morphological growth. The prepared thin films have potential applications in energy storage devices.
Article
Chemistry, Physical
Roopali Shekhawat, Vinod Erkkara Madhavan, K. Ramesh
Summary: This work reports the phase change properties of Ge2Sb2-xAsxTe5 thin films deposited by thermal evaporation. The As substituted samples exhibit higher crystallization temperatures, sharper transitions, and increased data retention. These As substituted Ge-Sb-Te alloys show great potential for PCRAM applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Analytical
Yi Lv, Qian Wang, Houpeng Chen, Chenchen Xie, Shenglan Ni, Xi Li, Zhitang Song
Summary: By designing a novel 2T2R structure circuit and a compressing encoding scheme, it is possible to increase the storage density of phase change memory and improve data reliability.
Article
Physics, Multidisciplinary
Hans Kessler, Phatthamon Kongkhambut, Christoph Georges, Ludwig Mathey, Jayson G. Cosme, Andreas Hemmerich
Summary: This study represents the first experimental realization of a time crystal stabilized by dissipation. The period doubled switching between distinct checkerboard density wave patterns in a driven open atom-cavity system is induced by controlled cavity dissipation, cavity-mediated interactions, and external driving. The research demonstrates the robustness of this dynamical phase against changes in system parameters and temporal perturbations of the driving.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Physical
Zhitang Song, Ruobing Wang, Yuan Xue, Sannian Song
Summary: This study focuses on nonvolatile phase change random access memory (PCRAM) and proposes the development of a homogeneous phase change material by constructing three matched octahedrons, leading to an overall improvement in performance.
Article
Materials Science, Multidisciplinary
Bing Wang, Guanjie Wang, Linggang Zhu, Jian Zhou, Zhimei Sun
Summary: This study investigates the doping effects of N on polycrystalline Ge1Sb2Te4 and reveals its microscopic effects in the presence of grain boundaries. The findings show that N can modify the electronic structure and enhance the performance of phase change memory cells.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Multidisciplinary Sciences
Jingon Jang, Seonghoon Jang, Sanghyeon Choi, Gunuk Wang
Summary: By implementing additional filter evaluation and a simple run-off election-based decision rule in artificial neural network systems, confusion is reduced and training and inference performance is improved, leading to increased classification accuracy of the data set.
SCIENTIFIC REPORTS
(2021)
Article
Multidisciplinary Sciences
Phatthamon Kongkhambut, Jim Skulte, Ludwig Mathey, Jayson G. Cosme, Andreas Hemmerich, Hans Kessler
Summary: In this study, we observed a limit cycle phase in a continuously pumped atom-cavity system, characterized by emergent oscillations in the photon number. This dynamical state spontaneously breaks continuous time translation symmetry and is robust against temporal perturbations, demonstrating the realization of a continuous time crystal.
Article
Materials Science, Multidisciplinary
N. Numan, A. Simo, B. Mabakachaba, I. G. Madiba, C. B. Mtshali, Z. M. Khumalo, N. Mongwaketsi, N. Mlungisi, M. Maaza
Summary: This article discusses the different equilibrium phases of VO2 in the oxygen-vanadium system and its applications in technology. By controlling the stoichiometry and polymorphs of the material through a sandwich structure, thermochromic properties can be achieved. The thickness of the middle layer also affects the phase transition performance.
