Unconventional Ferroelectricity with Quantized Polarizations in Ionic Conductors: High-Throughput Screening

Wang, Xuechen; Yang, Junyou; Wu, Menghao

doi:10.1021/acs.jpclett.2c02601

Cited by 10 publications

(13 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown in Figure 6a, if there are N proton vacancies in each hydrogen‐bonded chain formed by hydroxyl groups at the zigzag edges of a graphene nanoribbon, the polarization will be 0.62 + (N − 1)1.23 e Å per proton. Similar quantized ferroelectricity induced by mobile vacancies can be applied to some other hydrogen‐bonded ferroelectrics like alkali hydroxides, 69 metal oxyhydroxides, 70,77 and even some metal‐ion conductors with non‐ferroelectric crystal lattices 78 . For example, coexistence of two proton transfer modes and two distinct ferroelectricity are predicted in γ‐MOOH, as shown in Figure 6b, with different switching barriers and polarizations reversed respectively by proton hopping and swirling.…”

Section: Introductionmentioning

confidence: 52%

“…Similar quantized ferroelectricity induced by mobile vacancies can be applied to some other hydrogen-bonded ferroelectrics like alkali hydroxides, 69 metal oxyhydroxides, 70,77 and even some metal-ion conductors with non-ferroelectric crystal lattices. 78 For example, coexistence of two proton transfer modes and two distinct ferroelectricity are predicted in γ-MOOH, as shown in Figure 6b, with different switching barriers and polarizations reversed respectively by proton hopping and swirling. Which one will dominate depends on various factors including the intensity and direction of electric field, the existence of vacancies, and temperature.…”

Section: Hydrogen-bonded Ferroelectricitymentioning

confidence: 91%

“…In classical theory, the existence of ferroelectricity has been limited to 10 specific polar point groups. However, the predicted ferroelectricity with quantized polarizations in ZB silver monohalides, 81,93 honeycomb InBi monolayer, 92 and a series of ion conductors 78 with crystal lattices that belong to other point groups breaks such rule, which may be attributed to the long ion‐displacement crossing the unitcell that was not taken into account by conventional theory. Such unconventional ferroelectricity is yet to be experimentally verified in future.…”

Section: Introductionmentioning

confidence: 98%

See 2 more Smart Citations

Theoretical designs of low‐barrier ferroelectricity

Zhong

Gao

Yang

et al. 2023

WIREs Comput Mol Sci

Self Cite

View full text Add to dashboard Cite

Ferroelectrics with electrically switchable spontaneous polarizations can be used for information storage, where a low switching barrier is favorable to reduce the energy cost and enhance the speed for data writing. Meanwhile their robustness at working temperature should be ensured, which is a challenge for the designs of low‐barrier ferroelectrics. Here we review several types of ferroelectric mechanisms that may render both low switching barriers and room‐temperature robustness, which have been theoretically proposed in previous studies. (1) The prediction of sliding ferroelectricity with ultralow switching barriers has been experimentally confirmed in a series of van der Waals layers, which may enable convenient electrical control of various physical properties in 2D materials, like magnetic, photovoltaic, valleytronic and topological properties. (2) Hydrogen‐bonded ferroelectricity spontaneously formed by head‐to‐tail chains can be switched by proton‐transfer crossing a low barrier, and a mechanism of ultra‐high piezoelectricity utilizing the specific features of hydrogen bonding has been proposed. (3) High‐ionicity ferroelectricity induced by covalent‐like ionic bondings may entail high polarizations and low barriers during switching, which is attributed to the features of long‐range Coulomb interaction, and the long ion‐displacements crossing unitcell may give rise to unconventional ferroelectricity with quantized polarizations even in crystals of non‐ferroelectric point groups. Those low‐barrier ferroelectric mechanisms may bring in both new physics and technological advances, which are to be further explored.This article is categorized under: Structure and Mechanism > Computational Materials Science

show abstract

Section: Introductionmentioning

confidence: 52%

Section: Hydrogen-bonded Ferroelectricitymentioning

confidence: 91%

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Theoretical designs of low‐barrier ferroelectricity

Zhong

Gao

Yang

et al. 2023

WIREs Comput Mol Sci

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is known that many Li-ion materials such as Li 2 SrNb 2 O 7 exhibit ionic ability ( 21 ) due to the small size of Li ion, where local Li vacancies can be easily induced via applying a voltage. Similarly, in those lithium halides, the charge carriers induced by vacancies may screen part of the ferroelectric polarization, while the migration of vacancies may give rise to “ferroionicity,” where even one local vacancy in each conduction channel may induce a high switchable polarization ( 22 , 23 ).…”

Section: Resultsmentioning

confidence: 99%

Covalent-like bondings and abnormal formation of ferroelectric structures in binary ionic salts

Dai

2023

Sci. Adv.

Self Cite

View full text Add to dashboard Cite

In the Mooser-Pearson diagram, binary ionic compoundss form into nonpolar symmetrical structures with high coordination numbers, while wurtzite structures should appear in the covalent region. Their tetrahedral bonding configurations break the inversion symmetry, with polarizations almost unswitchable due to the high barriers of abrupt breaking and reformation of covalent bonds. Here, through first-principles calculations, we find some exceptional cases of highly ionic ferroelectric binary salts such as lithium halides, which may form into wurtzite structures with covalent-like sp 3 bondings, and the origin of these abnormal formations is clarified. Their high polarizations induced by symmetry breaking are switchable, with much smoother switching pathway refrained from abrupt bond breaking due to the long-range feature of Coulomb interactions. These covalent-like ionic bondings do reduce not only their ferroelectric switching barriers but also the phase transition barriers between polar and nonpolar phases, rendering high performance in applications such as nonvolatile memory and energy storage.

show abstract

“…Recently, it has been proposed that the introduction of longrange displacive modes could give rise to unconventional ferroelectricity with quantized polarizations. 12 In this context, even a single local vacancy in ubiquitous ionic conductors can induce significant polarization. In our study, (CETM) 2 InCl 5 • H 2 O exhibits a P−E "hysteresis loop" with an exceptionally large "remnant polarization", surpassing that of conventional ferroelectric materials with displacive ions within a unit cell.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

High, Multiple, and Nonvolatile Polarizations in Organic–Inorganic Hybrid [(CH₃)₃(CH₂CH₂Cl)N]₂InCl₅·H₂O for Memcapacitor

Lu,

Luo,

Zhou

et al. 2023

J. Am. Chem. Soc.

View full text Add to dashboard Cite

Dielectrics with high, nonvolatile, and multiple polarizations are required for fabricating memcapacitors that enable high parallelism and low energy consumption in artificial neuromorphic computing systems as artificial synapses. Conventional ferroelectric materials based on displacive and order−disorder types generally have difficulty meeting these requirements due to their low polarization values (∼150 μC/cm 2 ) and persistent electrical hysteresis loops. In this study, we report a novel organic−inorganic hybrid (CETM) 2 InCl 5 •H 2 O (CETM = (CH 3 ) 3 (CH 2 CH 2 Cl)N) exhibiting an intriguing polarization vs electric field (charge vs voltage) "hysteresis loop" and a record-high nonvolatile polarization over 30 000 μC/cm 2 at room temperature. The polarization is highly dependent on the period and amplitude of the ac voltage, showing multiple nonvolatile states. Electrochemical impedance spectroscopy, time-dependent current behavior, disparate resistor response in the dehydrated derivative (CETM) 2 InCl 5 , and the negative temperature dependence of ionic conductance support that the memcapacitor behavior of (CETM) 2 InCl 5 •H 2 O stems from irreversible longrange migration of protons. First-principles calculations further confirm this and clarify the microscale mechanism of anisotropic polarization response. Our findings may open up a new avenue for developing memcapacitors by harnessing the benefits of ion migration in organic−inorganic hybrids.

show abstract

Unconventional Ferroelectricity with Quantized Polarizations in Ionic Conductors: High-Throughput Screening

Cited by 10 publications

References 42 publications

Theoretical designs of low‐barrier ferroelectricity

Theoretical designs of low‐barrier ferroelectricity

Covalent-like bondings and abnormal formation of ferroelectric structures in binary ionic salts

High, Multiple, and Nonvolatile Polarizations in Organic–Inorganic Hybrid [(CH₃)₃(CH₂CH₂Cl)N]₂InCl₅·H₂O for Memcapacitor

Contact Info

Product

Resources

About

Unconventional Ferroelectricity with Quantized Polarizations in Ionic Conductors: High-Throughput Screening

Cited by 10 publications

References 42 publications

Theoretical designs of low‐barrier ferroelectricity

Theoretical designs of low‐barrier ferroelectricity

Covalent-like bondings and abnormal formation of ferroelectric structures in binary ionic salts

High, Multiple, and Nonvolatile Polarizations in Organic–Inorganic Hybrid [(CH3)3(CH2CH2Cl)N]2InCl5·H2O for Memcapacitor

Contact Info

Product

Resources

About

High, Multiple, and Nonvolatile Polarizations in Organic–Inorganic Hybrid [(CH₃)₃(CH₂CH₂Cl)N]₂InCl₅·H₂O for Memcapacitor