Actinium Hydrides AcH10, AcH12, and AcH16 as High-Temperature Conventional Superconductors

Semenok, Dmitrii V.; Kvashnin, Alexander G.; Kruglov, Ivan A.; Oganov, Artem R.

doi:10.1021/acs.jpclett.8b00615

Cited by 114 publications

(111 citation statements)

References 40 publications

Supporting

Mentioning

107

Contrasting

Order By: Relevance

“…As it can be seen in Figure 9, the maximum calculated Тс is reached in the 5th period and decreases in both directions along the crest of "HTSC-spine" as the period number reduces or increases. We marked a promising zone Cs-Fr-Ba-Ra where new HTSC phases like XH [9][10][11][12] with Тс in the range of 100-200 К at 150-200 GPa are expected to occur. These elements belonging to d-belt of superconductivity (s-d boundary 12 ) are similar to K, Ca, Sr which provide HTSC hydrides with the indicated compositions and, in addition, are adjacent to the group of La-Ac-Th that forms hydrides of the mentioned compositions with good SC properties as well.…”

Section: Discussionmentioning

confidence: 91%

“…At assessment of the maxT C, special attention should be drawn to XH [8][9][10][11][12] compositions. With further growth of n (> 20), the effect of metal center complexation becomes insignificant and we turn to the ultimate case of the almost pure hydrogen that will not transit to the superconducting state until 400-500 GPa.…”

Section: Discussionmentioning

confidence: 99%

“…In the Ba-H system the maximal value of T C = 31-38 K belongs to the BaH 6 at 100 GPa, 2 while for LaH 10 the maximal value of was predicted to be 286 K at 210 GPa. 10 After the maximum a sharp decline of maxT C occurs down to 13 K for Hf-H system (HfH 2 ) at 260 GPa, 12 while for the tantalum hydride Fdd2-TaH 6 was predicted as a superconductor with T C = 136 K at 300 GPa. 29 Hafnium has [Xe]4f 14 5d 2 6s 2 electronic configuration with two d-electrons where the only deep lying fully filled f-shell may negatively influent the superconducting properties of Hf-H phases.…”

Section: Period 6 Cs-ba-la-hf-tamentioning

confidence: 99%

See 2 more Smart Citations

On Distribution of Superconductivity in Metal Hydrides

Semenok

Kruglov

Savkin

et al. 2020

Current Opinion in Solid State and Materials Science

Self Cite

149

169

View full text Add to dashboard Cite

Distribution of superconducting properties among metal hydrides was investigated using stateof-the-art computational simulation techniques. We proposed a search rule for high-T C metalhydrogen systems based on analysis of electronic structure of atomic s, d, f-orbitals. Results of actinides and lanthanides study show that they form highly symmetric superhydrides XH 7-9 at relatively low pressures. However, actinides do not exhibit high-temperature superconductivity (except for Th-H system) and should not be considered as materials appropriate for experimental studies, as well as all d m -elements with m > 4 including metal hydrides of the precious elements. A refinement rule based on monotonic behavior of the maximum achievable critical temperature as a function of d+f electrons, maxT C (N d+f ), was proposed for already known materials. Using this rule, the reported T C values for the higher hydrides in K-H, Zr-H, Hf-H and Ti-H systems were corrected. The dependences of maxT C on the group number, period, pressure, and phase composition of hydrides were investigated. Developed model enables to make new targeted predictions relating to existence of new superconducting compounds. For Mg-H, Sr-H, Ba-H, Cs-H, Rb-H, we predict the existence of new high-T C phases XH n with n ≥ 10. Electron doping of H-sublattice by pressure-driven delocalization of d,f-electrons is suggested as the key factor for determining superconductive properties of polyhydrides. Graphical abstract:

show abstract

Section: Discussionmentioning

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Section: Period 6 Cs-ba-la-hf-tamentioning

confidence: 99%

See 1 more Smart Citation

On Distribution of Superconductivity in Metal Hydrides

Semenok

Kruglov

Savkin

et al. 2020

Current Opinion in Solid State and Materials Science

Self Cite

149

169

View full text Add to dashboard Cite

show abstract

“…[2]). In this regard, recently researchers could demonstrate a purely phonon-mediated SC with T c up to 250 K in actinium hydrides at 200 GPa [3]. The key insight of this work was the discovery of a link between chemical composition and SC.…”

Section: Introductionmentioning

confidence: 79%

Enhanced T_c and multiband superconductivity in the fully-gapped ReBe₂₂ superconductor

et al. 2019

View full text Add to dashboard Cite

In search of the origin of superconductivity (SC) in diluted rhenium superconductors and their significantly enhanced T c compared to pure Be (0.026 K), we investigated the intermetallic ReBe 22 compound, mostly by means of muon-spin rotation/relaxation (μSR). At a macroscopic level, its bulk SC (with T c =9.4 K) was studied via electrical resistivity, magnetization, and heat-capacity measurements. The superfluid density, as determined from transverse-field μSR and electronic specific-heat measurements, suggest that ReBe 22 is a fully-gapped superconductor with some multigap features. The larger gap value, D = 1.78 l 0 T k B c , with a weight of almost 90%, is slightly higher than that expected from the BCS theory in the weak-coupling case. The multigap feature, rather unusual for an almost elemental superconductor, is further supported by the field-dependent specific-heat coefficient, the temperature dependence of the upper critical field, as well as by electronic bandstructure calculations. The absence of spontaneous magnetic fields below T c , as determined from zero-field μSR measurements, indicates a preserved time-reversal symmetry in the superconducting state of ReBe 22 . In general, we find that a dramatic increase in the density of states at the Fermi level and an increase in the electron-phonon coupling strength, both contribute to the highly enhanced T c value of ReBe 22 .

show abstract

“…The following works refer to studies of binary hydrides under pressure for which some of the information was taken Fig. 21: Li [542], K [543], Fr [434], Be [544], Mg [545], Ca [176], Sr [546,547] Ba [548], Ra [434], Sc [549], Y [182], La [182,177], (Ce, Pr, Nd, Ho, Er, Tm, and Lu) [434], Ac [550], Th [551], Pa [434,552], U [553], (Np, Cm) [434], (Ti,Zr,Hf) [434], V [554], Nb [555,556], Ta [557], Cr [558], W [559], Tc [560], Ru [561], Os [562], (Rh,Ir) [563], Pd [440,564], Pt [565,566,563,567], Au [563], B [568], Al [569], Ga [570], In [571], Si [159,572], Ge [573,574,…”

Section: Appendixmentioning

confidence: 99%

A perspective on conventional high-temperature superconductors at high pressure: Methods and materials

et al. 2020

View full text Add to dashboard Cite

Two hydrogen-rich materials: H 3 S and LaH 10 , synthesized at megabar pressures have revolutionized the field of superconductivity by providing a first glimpse into the solution for the hundred-year-old problem of room-temperature superconductivity. The mechanism governing these exceptional superconductors is the conventional electron-phonon coupling. Here, we describe recent advances in experimental techniques, superconductivity theory and first-principles computational methods, which made this discovery possible. The aim of this work is to provide an up-to-date compendium of the available results on superconducting hydrides and explain the synergy of different methodologies that led to the extraordinary discoveries in the field. Furthermore, in an attempt to evidence empirical rules governing superconductivity in binary hydrides under pressure, we discuss general trends in electronic structure and chemical bonding. The last part of the Review introduces possible strategies to optimize pressure and transition temperatures in conventional superconducting materials. Directions for future research in areas of theory, computational methods and high-pressure experiments are proposed, in order to advance our understanding of superconductivity.

show abstract

Actinium Hydrides AcH₁₀, AcH₁₂, and AcH₁₆ as High-Temperature Conventional Superconductors

Cited by 114 publications

References 40 publications

On Distribution of Superconductivity in Metal Hydrides

On Distribution of Superconductivity in Metal Hydrides

Enhanced T_c and multiband superconductivity in the fully-gapped ReBe₂₂ superconductor

A perspective on conventional high-temperature superconductors at high pressure: Methods and materials

Contact Info

Product

Resources

About

Actinium Hydrides AcH10, AcH12, and AcH16 as High-Temperature Conventional Superconductors

Cited by 114 publications

References 40 publications

On Distribution of Superconductivity in Metal Hydrides

On Distribution of Superconductivity in Metal Hydrides

Enhanced Tc and multiband superconductivity in the fully-gapped ReBe22 superconductor

A perspective on conventional high-temperature superconductors at high pressure: Methods and materials

Contact Info

Product

Resources

About

Actinium Hydrides AcH₁₀, AcH₁₂, and AcH₁₆ as High-Temperature Conventional Superconductors

Enhanced T_c and multiband superconductivity in the fully-gapped ReBe₂₂ superconductor