Pressure-induced monotonic enhancement of Tc to over 30 K in superconducting Pr0.82Sr0.18NiO2 thin films

Abstract

The successful synthesis of superconducting infinite-layer nickelate thin films with the highest Tc ≈ 15 K has ignited great enthusiasm for this material class as potential analogs of the high-Tc cuprates. Pursuing a higher Tc is always an imperative task in studying a new superconducting material system. Here we report high-quality Pr0.82Sr0.18NiO2 thin films with Tconset ≈ 17 K synthesized by carefully tuning the amount of CaH2 in the topotactic chemical reduction and the effect of pressure on its superconducting properties by measuring electrical resistivity under various pressures in a cubic anvil cell apparatus. We find that the onset temperature of the superconductivity, Tconset, can be enhanced monotonically from ~17 K at ambient pressure to ~31 K at 12.1 GPa without showing signatures of saturation upon increasing pressure. This encouraging result indicates that the Tc of infinite-layer nickelates superconductors still has room to go higher and it can be further boosted by applying higher pressures or strain engineering in the heterostructure films.

Photoinduced Phase Transition in Infinite‐Layer Nickelates

“…[21,25] Overall, we prepared the high-quality infinite-layer NdNiO 2 thin films with recognizable atomic steps by softer reduction process with relatively lower anneal temperature and longer reduction time compared with our previous work. [34] The Intrinsic temperature-dependent resistivity 𝜌(T) of both the perovskite NdNiO 3 and infinite-layer NdNiO 2 thin films are shown as Figure 1h. The perovskite NdNiO 3 film goes on the first-order metal-insulator transition from the high-temperature paramagnetic metal to the low-temperature antiferromagnetic insulator.…”

“…However, the incompletely controllable sample preparation process greatly limited the further study of nickelate superconductors, in other words, it is extremely difficult to obtain the high-quality singlecrystalline precursor perovskite films, and the following topological chemical reduction usually results in the infinite-layer crystal structural degradation. [21,33,34] Lately, the spectroscopic and calculation results suggest that the infinite-layer nickelate system falls in the Mott-Hubbard regime rather than the charge-transfer configuration reported in cuprates. [35][36][37][38] In other words, ReNiO 2 (Re represents rare earth elements: La, Pr, and Nd), the parent of nickelate superconductor, is defined as self-doping Mott insulator in the Mott-Kondo scenario, and the "self-doping effect" derives from the Re-5d orbitals that hybridize with the Ni-3d orbitals and cross the Fermi level, leading to small Fermi pockets of dominantly itinerant Re-5d electrons.…”

Giant Pressure‐Induced Spectral Shift in Cyan‐Emitting Eu2+‐Activated Sr8Si4O12Cl8 Microspheres for Ultrasensitive Visual Manometry

“…[ 1–3 ] When materials undergo a compression process triggered by high‐pressure conditions, some unique phenomena may occur, such as phase transitions, formation of new compounds, defects generation, local symmetry modification, and so forth. [ 4–6 ] Nowadays, to apply static high‐pressure in the laboratory, the diamond anvil cell (DAC) system is widely used, in which optical pressure monitoring is available due to the high transparency of diamonds in a broad spectral range, i.e., from ultraviolet (UV), via visible to near‐infrared (NIR) light. [ 7,8 ] In order to monitor the static pressure in a DAC chamber, luminescent materials, in which lanthanide or transition metal ions act as activators, are often used by analyzing their pressure‐dependent spectral characteristics, such as band position, full width at half maximum (FWHM), emission decay time and band ratio.…”

“…[1][2][3] When materials undergo a compression process triggered by highpressure conditions, some unique phenomena may occur, such as phase transitions, formation of new compounds, defects generation, local symmetry modification, and so forth. [4][5][6] Nowadays, to apply static high-pressure in the laboratory, the them are only suitable for measuring very high-pressures, i.e., they do not exhibit linear/monotonous spectral shift within the relatively low-pressure regime. That is why, in the "low-pressure range" (below ≈10 GPa), where organic compounds and various soft materials can undergo several phase transitions, there is an "empty" pressure monitoring window that requires highly sensitivity optical manometers.…”

Effects of rare-earth magnetism on the superconducting upper critical field in infinite-layer nickelates

“…One exception is in PrBa 2 Cu 3 O 7−δ , where coincidental hybridization between the Pr 4f and oxygen 2p states is believed to compete with the emergence of superconductivity (11). In contrast, in the nickelate superconductors, there is consistent transport, spectroscopic, and theoretical evidence for hybridization between a broad range of R 5d orbitals and the Ni 3d orbitals (2)(3)(4)(5)(6)(7)(8)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24). An open question currently under debate is the potential role of the R 4f electrons (25)(26)(27)(28).…”