Synergy effect of co-doping Sc and Y in Sb<sub>2</sub>Te<sub>3</sub> for phase-change memory

Hu, Shuwei; Xiao, Jing; Zhou, Jian; Elliott, S. R.; Sun, Zhimei

doi:10.1039/d0tc01693d

Cited by 31 publications

(24 citation statements)

References 55 publications

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“…In addition to the commonly used germanium alloying, a large proportion of main‐group and transition‐metal elements in the periodic table have been screened, both in simulations and experiments, with scandium and yttrium emerging as the optimal dopants. [ 10 ] Codoping with Sc and Y was found to be a synergistic approach to further improve the properties of Sb 2 Te 3 for PCM applications, [ 11 ] whereas nanostructuring at the device level, such as forming alternating layers of Sb 2 Te 3 and TiTe 2 , was found to have a dramatic impact on reducing the time‐dependent resistance drift and improving the stability of the amorphous state. [ 12 ] Because of all of these recent results, Sb 2 Te 3 has come to the forefront of PCM technology.…”

Section: Figurementioning

confidence: 99%

On the Chemical Bonding of Amorphous Sb₂Te₃

Mocanu

Konstantinou

Mavračić

et al. 2020

Physica Rapid Research Ltrs

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An analysis of the electronic structure and chemical bonding in glassy Sb2Te3 is carried out by means of density functional theory calculations, on a computer model generated by ab initio molecular dynamics. A significant antibonding character of electronic states below the Fermi level is observed, which is the characteristic feature of phase‐change memory materials. Near‐linear chains, with alternating long and short bonds, are found to be an important geometric structural pattern related to this antibonding signature. The electronic structure and chemical bonding analysis, herein, reveals an emergent character of hypervalent interactions in the amorphous phase of Sb2Te3. The intimate link between these near‐linear chains, hypervalent interactions, and the fast‐switching properties of this technologically important material provides valuable information for the future development of phase‐change memory materials.

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Section: Figurementioning

confidence: 99%

On the Chemical Bonding of Amorphous Sb₂Te₃

Mocanu

Konstantinou

Mavračić

et al. 2020

Physica Rapid Research Ltrs

Self Cite

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“…S7 †). [53][54][55] Despite the low degree of graphitization according to the XRD and Raman results, XPS results conrm a large content of sp 2 character in p aromatic form. The presence of such sp 2 in p aromatic system could enhance electric conductivity 32 which is desired in applications to supercapacitors.…”

Section: View Article Onlinementioning

confidence: 99%

Green and sustainable zero-waste conversion of water hyacinth (Eichhornia crassipes) into superior magnetic carbon composite adsorbents and supercapacitor electrodes

et al. 2019

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Troublesome aquatic weed, water hyacinth (Eichhornia crassipes) was converted into solid and liquid fractions via green and energy-saving hydrothermal carbonization (HTC). The solid product, hydrochar, was employed as a precursor to prepare magnetic carbon materials by simple activation and magnetization using KOH and Fe 3+ ions, respectively. The obtained magnetic adsorbent possessed good magnetic properties and presented outstanding capacities to adsorb methylene blue (524.20 mg g À1 ), methyl orange (425.15 mg g À1 ) and tetracycline (294.24 mg g À1 ) with rapid adsorption kinetics even at high concentrations (up to 500 mg L À1 ), attributed to high specific surface area and mesopore porosity.Besides the solid hydrochar, the water-soluble liquid product was used to fabricate carbon-based supercapacitors through facile KOH activation with a considerably lower KOH amount in comparison to conventional activation. The supercapacitor electrode made from activated liquid product possessed an extremely high specific surface area of 2545 cm 2 g À1 and showed excellent specific capacitance (100 F g À1 or 50 F cm À3 at 1 A g À1 ) and good retention of capacitance (92% even after 10 000 cycles). This work demonstrated that both solid and liquid HTC fractions from this bio-waste can serve as effective sources to prepare functional carbon materials, making this approach a sustainable zero-waste biomass conversion process. Scheme 1The preparation steps of magnetic adsorbent (MWHHTC(1)-800) and carbon-based supercapacitor (CLP + KOH-800) using water hyacinth as a carbon precursor.This journal is

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“…Ab initio materials screening studies have recently shown that alloying with a suitable element, such as Sc [10][11][12][13][14][15] or Y [16][17][18][19] , can largely increase the nucleation rate to improve switching speed at elevated temperatures. The recently designed Sc 0.2 Sb 2 Te 3 (SST) alloy brings the programming time down to~0.7 ns, expanding the capability of PRAM for cache-type memory applications [10][11][12][13][14][15] .…”

Section: Introductionmentioning

confidence: 99%

Ab initio molecular dynamics and materials design for embedded phase-change memory

et al. 2021

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The Ge2Sb2Te5 alloy has served as the core material in phase-change memories with high switching speed and persistent storage capability at room temperature. However widely used, this composition is not suitable for embedded memories—for example, for automotive applications, which require very high working temperatures above 300 °C. Ge–Sb–Te alloys with higher Ge content, most prominently Ge2Sb1Te2 (‘212’), have been studied as suitable alternatives, but their atomic structures and structure–property relationships have remained widely unexplored. Here, we report comprehensive first-principles simulations that give insight into those emerging materials, located on the compositional tie-line between Ge2Sb1Te2 and elemental Ge, allowing for a direct comparison with the established Ge2Sb2Te5 material. Electronic-structure computations and smooth overlap of atomic positions (SOAP) similarity analyses explain the role of excess Ge content in the amorphous phases. Together with energetic analyses, a compositional threshold is identified for the viability of a homogeneous amorphous phase (‘zero bit’), which is required for memory applications. Based on the acquired knowledge at the atomic scale, we provide a materials design strategy for high-performance embedded phase-change memories with balanced speed and stability, as well as potentially good cycling capability.

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Synergy effect of co-doping Sc and Y in Sb₂Te₃ for phase-change memory

Abstract: Co-doping Sc and Y is a feasible way to obtained better-performance and moderate-cost Sb2Te3 phase-change materials.

Cited by 31 publications

References 55 publications

On the Chemical Bonding of Amorphous Sb₂Te₃

On the Chemical Bonding of Amorphous Sb₂Te₃

Green and sustainable zero-waste conversion of water hyacinth (Eichhornia crassipes) into superior magnetic carbon composite adsorbents and supercapacitor electrodes

Ab initio molecular dynamics and materials design for embedded phase-change memory

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Synergy effect of co-doping Sc and Y in Sb2Te3 for phase-change memory

Abstract: Co-doping Sc and Y is a feasible way to obtained better-performance and moderate-cost Sb2Te3 phase-change materials.

Cited by 31 publications

References 55 publications

On the Chemical Bonding of Amorphous Sb2Te3

On the Chemical Bonding of Amorphous Sb2Te3

Green and sustainable zero-waste conversion of water hyacinth (Eichhornia crassipes) into superior magnetic carbon composite adsorbents and supercapacitor electrodes

Ab initio molecular dynamics and materials design for embedded phase-change memory

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Product

Resources

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Synergy effect of co-doping Sc and Y in Sb₂Te₃ for phase-change memory

On the Chemical Bonding of Amorphous Sb₂Te₃

On the Chemical Bonding of Amorphous Sb₂Te₃