Ion transfer in solid solutions of Cu2Se and Ag2Se superionic conductors

Балапанов, М. Х.; Yakshibaev, R. A.; Mukhamed’yanov, U. Kh.

doi:10.1134/1.1568997

Cited by 21 publications

(10 citation statements)

References 11 publications

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“…Superionic conductors find technological applications in energy storage devices and selective gas pressure monitors. Moreover, Balapanov et al reported very large ionic thermoelectromotive force coefficients in copper-and silver based selenides [3]; therefore an implementation of these materials in thermoelectric devices is of considerable interest [3].…”

Section: Introductionmentioning

confidence: 99%

High-temperature behaviour of average structure and vibrational density of states in the ternary superionic compound AgCuSe

et al. 2006

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Abstract.Results of simultaneous thermal analysis (STA), synchrotron powder diffraction (in the range 300-973 K) and inelastic neutron scattering (at 285 and 505 K) on non-superionic β-and superionic α-AgCuSe are reported. The sample is stable in argon on heating. The volume change at the superionic phase transition is about 5%. A model for the average structure of α-AgCuSe is proposed. No anomalies in the temperature dependence of the parameters of the average structure were revealed. Ionic conductivity in α-AgCuSe can originate from cation jumps in "skewed" 100 directions between nearest-neighbour tetrahedral sites via the peripheries of the octahedral cavities. A correlation between the temperature dependence of the cation redistribution in α-AgCuSe and the temperature dependence of the ionic conductivity is supposed. Various contributions (anharmonic effects, time-average static disorder and phononphonon scattering) to the widths of individual phonons upon temperature increase lead to pronounced changes in the neutron-weighted densities of states of β-and α-AgCuSe and accompany the superionic phase transition as well. PACS

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Section: Introductionmentioning

confidence: 99%

High-temperature behaviour of average structure and vibrational density of states in the ternary superionic compound AgCuSe

et al. 2006

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“…[36,68] Other Cu and Ag-based superionic conductor also show migration barrier energies in the range of 0.1-0.3 eV (e.g., Cu 2 Se, Ag 2 Se, AgCrSe 2 , CuCrSe 2 , Ag 8 SnSe 6 ). [44,64,69,70] We now investigate the coupling of intercluster Cu + jumps with the framework and its dynamics. Figure 1b shows the Cu + sites and surrounding PSe 4 3− tetrahedra in the s-cubic phase.…”

Section: Molecular Dynamics Simulations Of Qens and Diffusionmentioning

confidence: 99%

Strongly Anharmonic Phonons and Their Role in Superionic Diffusion and Ultralow Thermal Conductivity of Cu₇PSe₆

Gupta

Ding

Bansal

et al. 2022

Advanced Energy Materials

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The quest for advanced superionic materials requires understanding their complex atomic dynamics, but detailed studies of the interplay between lattice vibrations and ionic diffusion remain scarce. Here inelastic and quasielastic neutron scattering measurements in the superionic argyrodite Cu7PSe6 are reported, combined with molecular dynamics (MD) based on ab initio and machine‐learned potentials, providing critical insights into the atomistic mechanisms underlying fast ion conduction. The results reveal how long‐range Cu diffusion is limited by intercluster hopping, controlled by selective anharmonic phonons of the crystalline framework. Further, the Green–Kubo simulations reproduce the ultralow lattice thermal conductivity and identify contributions from mobile ions, phonons, and their cross‐correlations. The mode resolved analysis shows that the thermal conductivity is dominated by low‐energy acoustic phonon modes of the overall crystal framework. The analysis of mode‐resolved spectral functions further show that vibrational modes with significant Cu contributions are strongly damped, corresponding to the breakdown of associated phonon quasiparticles. These results highlight the importance of strongly anharmonic effects in superionic systems, in which the traditional quasiharmonic phonon picture is insufficient, and pave the way toward combining machine‐learning accelerated simulations with neutron scattering experiments to rationalize the complex atomic dynamics underlying ionic and thermal transport.

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“…The material becomes superionic, with the conductivity of Cu ? ions as high as 2.5 S/cm at 623 K [11].…”

Section: Graphical Abstract Introductionmentioning

confidence: 97%

The unstable thermoelectric effect in non-stoichiometric Cu2Se during the non-equilibrium phase transition

2021

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The superionic α ↔ β phase transition in Cu1.96Se thermoelectric material is investigated by means of thermal analysis (DSC) and measurements of Seebeck coefficient and electrical conductivity. Results of the DSC measurements with 1–10 K/min heating and cooling rates show that the material is close to the equilibrium phase composition during the transformation. However, the kinetic limitation of the process exists, which is indicated by supercooling. At the beginning of the β → α transition, the most significant kinetic delay was attributed to the nucleation of the α phase. During the phase transformation, the Seebeck coefficient was lower than in a stabilised material (measured with 0.1 K/min heating/cooling rate). During cooling, a decrease from 130 μV/K (in a stabilised measurement) to 7 μV/K (5 K/min cooling rate) was observed. The deviation from the expected values of the Seebeck coefficient was correlated with the difference between the actual and equilibrium phase compositions. Graphical abstract

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Ion transfer in solid solutions of Cu2Se and Ag2Se superionic conductors

Cited by 21 publications

References 11 publications

High-temperature behaviour of average structure and vibrational density of states in the ternary superionic compound AgCuSe

High-temperature behaviour of average structure and vibrational density of states in the ternary superionic compound AgCuSe

Strongly Anharmonic Phonons and Their Role in Superionic Diffusion and Ultralow Thermal Conductivity of Cu₇PSe₆

The unstable thermoelectric effect in non-stoichiometric Cu2Se during the non-equilibrium phase transition

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Ion transfer in solid solutions of Cu2Se and Ag2Se superionic conductors

Cited by 21 publications

References 11 publications

High-temperature behaviour of average structure and vibrational density of states in the ternary superionic compound AgCuSe

High-temperature behaviour of average structure and vibrational density of states in the ternary superionic compound AgCuSe

Strongly Anharmonic Phonons and Their Role in Superionic Diffusion and Ultralow Thermal Conductivity of Cu7PSe6

The unstable thermoelectric effect in non-stoichiometric Cu2Se during the non-equilibrium phase transition

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Strongly Anharmonic Phonons and Their Role in Superionic Diffusion and Ultralow Thermal Conductivity of Cu₇PSe₆