Two-band superconductivity and transition temperature limited by thermal fluctuations in ambient pressure La3-xPrxNi2O7-d (x = 0.0, 0.15, 1.0) thin films DOI Creative Commons
E. F. Talantsev

Опубликована: Фев. 3, 2025

Recently, two research groups [1–3] reported on the observation of ambient pressure superconductivity in a few nanometers thick La3-xPrxNi2O7-d (x = 0.0, 0.15, 1.0) films with T(c,onset)≅40 K and T(c,zero)≤14 K. Here I have analyzed self-field critical current density, J_c (sf,T), upper field, Bc2 (T), for these films1–3 showed that exhibit large in-plane London penetration depth, λab(0)=1.9-6.8 μm, Ginzburg-Landau parameter κ(0)=500-1000. Deduced λab(0) values are within uncertainty range independently [2] λab(T=1.8 K)=(3.7±1.9) μm. Such explain wide resistive transition [1–3], because implies low superfluid ρs≡1/(λab)^2 , therefore thermal fluctuations. Consequently, calculated phase fluctuation temperature, Tfluc, found T(c,zero)<T_fluc. also Jc(sf,T) (T) data nicely fitted to two-band gap models, from which preference has been given (s+s)-wave model (for ratios (2ΔL(0))/(kBT(c,L) )≅3.6-4.0 (2ΔS(0))/(kBT(c,S) )=1.0-3.0 larger smaller bands, respectively). Besides bulk highly compressed Ruddlesden–Popper nickelates Lan+1NinO3n+1 (n 2,3) Lan+1NinO2n+2 5) thin film demonstrate evidence superconductivity.

Язык: Английский

Two-band superconductivity and transition temperature limited by thermal fluctuations in ambient pressure La3-xPrxNi2O7-d (x = 0.0, 0.15, 1.0) thin films DOI Creative Commons
E. F. Talantsev

Опубликована: Фев. 3, 2025

Recently, two research groups [1–3] reported on the observation of ambient pressure superconductivity in a few nanometers thick La3-xPrxNi2O7-d (x = 0.0, 0.15, 1.0) films with T(c,onset)≅40 K and T(c,zero)≤14 K. Here I have analyzed self-field critical current density, J_c (sf,T), upper field, Bc2 (T), for these films1–3 showed that exhibit large in-plane London penetration depth, λab(0)=1.9-6.8 μm, Ginzburg-Landau parameter κ(0)=500-1000. Deduced λab(0) values are within uncertainty range independently [2] λab(T=1.8 K)=(3.7±1.9) μm. Such explain wide resistive transition [1–3], because implies low superfluid ρs≡1/(λab)^2 , therefore thermal fluctuations. Consequently, calculated phase fluctuation temperature, Tfluc, found T(c,zero)<T_fluc. also Jc(sf,T) (T) data nicely fitted to two-band gap models, from which preference has been given (s+s)-wave model (for ratios (2ΔL(0))/(kBT(c,L) )≅3.6-4.0 (2ΔS(0))/(kBT(c,S) )=1.0-3.0 larger smaller bands, respectively). Besides bulk highly compressed Ruddlesden–Popper nickelates Lan+1NinO3n+1 (n 2,3) Lan+1NinO2n+2 5) thin film demonstrate evidence superconductivity.

Язык: Английский

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