Effect of carbon doping on the structure of amorphous GeTe phase change material

Ghezzi, G.; Raty, Jean‐Yves; Maîtrejean, S.; Roule, A.; Elkaı̈m, Erik; Hippert, F.

doi:10.1063/1.3651321

Cited by 67 publications

(73 citation statements)

References 14 publications

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“…This is particularly important for embarked applications, such as in automobiles. It was shown experimentally that the crystallization temperature of GeTe is increasing upon doping (alloying) with some light elements, such as C and N [60], as shown in Table 18.2. This increase is linked to an increase in activation energy.…”

Section: Dynamical Approach To Stabilitymentioning

confidence: 98%

Amorphous Phase Change Materials: Structure, Stability and Relation with Their Crystalline Phase

Raty

Otjacques

Peköz

et al. 2015

Molecular Dynamics Simulations of Disordered Materials

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Phase Change Materials should be stable enough in their amorphous phase to achieve a durable data retention, however they should also be bad glass formers to be able to recrystallise at high speed. To understand these contradicting properties, we construct models of amorphous Ge-Sb-Te systems using Ab Initio Molecular Dynamics and analyse the structures in relation with the relevant crystalline state. We show that structural patterns that are precursors of the crystalline phase exist in the amorphous state and we identify the signature of the various types of local atomic orders in the X-ray absorption spectra that we compute using Density Functional Theory. We first analyse the mechanical properties of the amorphous phase in the framework of the Maxwell rigidity theory, showing that all efficient Phase Change Materials deviate from the perfect glass and are mechanically stressed-rigid. Additionally, we show that the stability of Phase Change Materials is related to the density of low frequency vibrational modes (Boson peak). We describe how an adequate doping can result in an increased stability of the amorphous phase while keeping intact the phase change ability of the material.

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Section: Dynamical Approach To Stabilitymentioning

confidence: 98%

Amorphous Phase Change Materials: Structure, Stability and Relation with Their Crystalline Phase

Raty

Otjacques

Peköz

et al. 2015

Molecular Dynamics Simulations of Disordered Materials

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“…AIMD simulations of a similar composition of C-doped GeTe ((Ge 0.52 Te 0.48 ) 0.85 C 0.15 ) have been performed [10]. It was found that in the simulated amorphous models, the C dopant atoms preferentially bond to Ge atoms and also to other C atoms, forming C-C-C chains.…”

Section: Carbon Dopingmentioning

confidence: 99%

Ab Initio Molecular-Dynamics Simulations of Doped Phase-Change Materials

Skelton

Lee

Elliott

2015

Molecular Dynamics Simulations of Disordered Materials

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The physical behaviour and device performance of phase-change, non-volatile memory materials can often be improved by the incorporation of small amounts of dopant atoms. In certain cases, new functionality can also be introduced, for example a contrast in magnetic properties between amorphous and crystalline phases of the host phase-change material when certain transition-metal dopants are included. This Chapter reviews some of the experimental data relating to doped phase-change materials and, in particular, a survey is given of the role played by molecular-dynamics simulations in understanding the atomistic mechanisms involved in the doping process. In addition, some examples are given of the in silico discovery of new phase-change compositions resulting from ab initio molecular-dynamics (AIMD) simulations.

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“…However, the binary compound GeTe with different doping [6], InSbTe [7], InGeTe [8], and GaSbTe [9] alloys are also under scrutiny for their higher crystallization temperature of interest for applications at high temperatures, e.g. in automotive electronics.…”

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confidence: 99%

Functional Properties of Phase Change Materials from Atomistic Simulations

Caravati

Sosso

Bernasconi

2015

Molecular Dynamics Simulations of Disordered Materials

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Chalcogenide alloys are materials of interest for optical recording and electronic nonvolatile memories. These applications rest on an ensemble of functional properties: a fast and reversible transformation between the amorphous and the crystalline phase upon heating and a strong optical and electronic contrast between the two phases that allow discriminating the two states of the memory. We discuss the insights gained from atomistic simulations based on Density Functional Theory on the functional properties of the prototypical phase change compounds Ge 2 Sb 2 Te 5 and GeTe. We review the results on the structural and bonding properties of the crystalline and amorphous phases, the origin of the optical and electronic contrast between the two phases and the source of the fast crystallization of the supercooled liquid. The results on the crystallization kinetics obtained from large scale simulations with interatomic potentials based on Neural Network methods are also discussed.

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Effect of carbon doping on the structure of amorphous GeTe phase change material

Cited by 67 publications

References 14 publications

Amorphous Phase Change Materials: Structure, Stability and Relation with Their Crystalline Phase

Amorphous Phase Change Materials: Structure, Stability and Relation with Their Crystalline Phase

Ab Initio Molecular-Dynamics Simulations of Doped Phase-Change Materials

Functional Properties of Phase Change Materials from Atomistic Simulations

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